Compositions and methods for gender sorting

ABSTRACT

A yeast based transactivation assay for gender sorting is disclosed.

[0001] This application claims priority to U.S. Provisional Application No. 60/286,010, filed Apr. 23, 2001, the entire disclosure of which is incorporated by reference herein.

FIELD OF THE INVENTION

[0002] The present invention relates to a novel method for detection of target molecules, such as hormones, using a yeast-based transactivation system. More particularly, the invention relates to methods for accurate and efficient gender sorting in mammalian and avian species.

BACKGROUND OF THE INVENTION

[0003] Various publications and patent documents are referenced in this application to describe the state of the art to which the invention pertains. Complete citations for these references are found at the end of the specification. Each of these publications or patents is incorporated by reference herein.

[0004] Sex separation of chicks at hatch is an important aspect of the poultry industry. The US poultry industry produces 8.9 billion broilers, 360 million broiler breeders, 360 million turkeys and 1.6 billion layers annually. These annual production numbers equate to roughly 160 million birds hatched each day which need to be sexed. Varied segments of the poultry industry must sex segregate offspring for different reasons. All turkeys are sex segregated due to the large differences in the growth rate, market age, management practices and nutritional requirements between male and female birds. In the layer or table egg industry, chicks must be sexed at hatch as only the females, or birds which lay eggs, are kept while all male chicks are discarded. The broiler breeder and turkey breeder industries produce both male and female lines that are eventually crossed to produce a hybrid commercial bird. The males or off-sex chicks produced from the female lines are discarded while the female chicks or off-sex chicks from the male lines are discarded. Disposal of unwanted chicks creates animal welfare and waste disposal issues for the industry. The meat type chicken or broiler industry prefer to sex segregate males from females to gain feed efficiency, improve uniformity at the processing plant and reduce production costs. The broiler industry often refrains from sex separate rearing due to the high costs of sexing and the need for trained sexers. A higher percentage of the broiler industry would sex segregate if a rapid, inexpensive, automated method were available.

[0005] Current sexing methods used in the poultry industry involve manual procedures that require highly trained professionals with specialized skills. Sexing methods involve either the Japanese method of vent sexing or feather sexing of chicks that carry a slow feathering gene (1, 2, 3). The manual sexing methods have several drawbacks. These include: 1) scheduling of manual labor; 2) increased processing time before chicks can be placed in the field with access to food and water; and 3) stress and damage to the chicks or poults. Manual sexing remains one of the few manual processing steps practiced in the highly automated poultry industry.

[0006] The Japanese or vent sexing method originated in the 1920's when the Japanese discovered that within the first or second fold of a chick's vent there are distinctive characteristics such as spots, lines and folds that reveal its sex (4, 5). Vent sexing is considered an art and generally practiced only by Asian individuals with excellent manual dexterity and Zen-like concentration (6). Vent sexers attend school for six months and then undergo a trainee program for two to five years until they are considered a qualified sexer based on speed and accuracy. Qualified sexers can vent sex 2,000 chicks per hour at 98% accuracy but only 5 to 10% of individuals attending vent sexing school attain qualified sexer status (6). The rapid rate at which a vent sexer must pick up, sex and sort baby chicks can result in a 1.4 to 1.8% increase in cull rate and 0.5 to 1.0% increase in early chick mortality due to chick damage during handling (7). Vent sexers are contract workers who travel from hatchery to hatchery working long tedious hours. Travel of these contract workers from hatchery to hatchery poses a bio-security threat for the poultry industry.

[0007] Feather sexing of chickens inbred for the K gene for slow feathering is the other commonly used method for sex segregation at hatch (3). Day-old chicks carrying the K gene can be sex segregated by examining the relative length of the primary and covert feathers of the wing, with the females carrying genes for fast feathering and the males carrying genes for slow feathering. Feather sexing is less expensive than vent sexing and does not require as skilled a labor force. Feather sexing is not applicable to turkeys, the majority of broiler breeds, some layer breeds, and also carries disadvantages. The k gene for slow feathering is closely linked to an endogenous virus (8), which can cause immunological tolerance to lymphoid leukosis (9) and is therefore a disadvantage in breeding stock. It is noteworthy that slow feathering males usually do not feather well in the brooder house especially during hot weather which often results in slower growth and increased cannibalism and that females carrying the K gene exhibit reduced egg production. Some poultry breeds exhibit sex specific color differences in feathers, however these breeds are not as commercially viable as other breeds. Color sexing can result in a higher rate of sexing mistakes than feather sexing.

[0008] Methods to sex segregate eggs before hatching have been previously attempted without success. A sex-linked gene, S^(al) for imperfect albinism was reported by Hutt and Cole (10) to have the potential to sex chicks at one day of age on the basis of eye color. The albino female chicks have pink eyes while the normal males have black eyes. The difference in eye color can also be used to accurately sex segregate embryos by candling the eggs on Day 10 of incubation. Candling or light illumination of the intact egg reveals the dark eye of the male chicken embryo but not the pink eye of the albino female. Use of the S^(a1) gene to sex segregate poultry was not pursued as the gene carries deleterious effects in turkeys and negative production effects in chickens.

[0009] Development of a quick, accurate, inexpensive automated method to sex segregate eggs before hatching would significantly increase profitability of the global broiler industry. Automated sexing gives rise to several benefits. These include 1) better feed and processing efficiencies; 2) reduced incubation space requirements; 3) greater selection of breeds without constraints of selection for a slow feathering gene; 4) reduced liability and reliability concerns associated with eliminating manual labor; 5) speedier hatchery processing; and 6) reduced animal welfare concerns associated with discarding male chicks in the layer egg industry.

[0010] In light of all the foregoing, the development of a quick, inexpensive, automated method to sex segregate eggs before hatching is highly desirable.

SUMMARY OF THE INVENTION

[0011] The present invention provides a method and kit for detecting target molecules in a sample. In a preferred embodiment, methods and kits for determining the sex of avian species while in the egg are disclosed. The cell-based sensor has additional applications in detection of glucuronidated steroid hormones, metabolites and xenobiotics. The ultra sensitive method of the invention may also be used to advantage to gender sort other animal species, and to assess patient populations for their susceptibility to drugs and predisposition to disease.

[0012] In an exemplary embodiment of the invention, a biological sample containing a sex-indicating hormone is isolated from the egg. Genetically engineered host cells comprising a sex hormone-dependent transactivation system are then contacted with the biological fluid. The engineered cells respond to the level of sex hormone by activating a reporter gene. Female eggs, which contain a significant amount of 17 β estradiol, a hormone that is absent from male embryos, give a positive response in cell-based sensor assays of the invention and are sorted as females.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a graph showing the difference of estradiol levels in pg/ml in the allantoic fluid of male and female broiler 17-day old embryos.

[0014]FIGS. 2A-2C are schematic diagrams of the estrogen-dependent transactivation system of the present invention.

[0015]FIG. 3A is a schematic diagram of the LacZ-reporter gene with estrogen response elements (ERES). The yeast reporter plasmid, YRpE2, contains two copies of an ERE (Lyttle et al., 1992) located upstream of the iso-1-cytochrome c (CYC1) promoter which is coupled to the E. coli beta-galactosidase gene (lacZ). This yeast-E. coli multicopy shuttle plasmid contains URA3 as a yeast transformation marker.

[0016]FIG. 3B is a schematic diagram of the LacZ-reporter gene with EREs. The yeast reporter plasmid, YRpE2SSA4-lacZ, contains two copies of an ERE (Lyttle et al., 1992) located upstream of the yeast heat shock inducible (SSA4, Genbank Accession number: J05637) promoter which is coupled to the E. coli beta-galactosidase gene (lacZ). This yeast-E. coli multicopy shuttle plasmid contains URA3 as a yeast transformation marker.

[0017]FIG. 4 (YEpE12-ERα) is a schematic diagram of the yeast expression plasmid utilized in the practice of the present invention (Graumann et al., 1996). A yeast expression plasmid is shown which encodes full-length human estrogen receptor alpha. The coding sequence is inserted into the yeast expression vector to produce a ubiquitin (UBI)-fusion protein under the control of a CUP1 promoter. TRP1 is the tryptophan selectable marker and 2 μm is for replicating yeast DNA.

[0018]FIG. 5 (pRS425-GPD-Ub-GUS) shows the yeast expression plasmids for expressing the E. coli GUS (beta-glucuronidase gene; Jefferson et al, 1986). The N-terminal coding sequence of the GUS gene is fused in frame with the C-terminal of the human ubiquitin gene. The recombinant protein is under GPD promoter. LEU2 is the leucine (LEU2) selectable marker and 2 μm facilitates replication in yeast.

[0019]FIGS. 6A and 6B show a pair of graphs showing that the gender sorting system of the invention efficiently sorts male and female turkeys as well as layer chickens.

[0020]FIG. 7 is a graph showing a transactivation assay using resorufin at concentration 0.00025 mg/mL and allantoic fluids (20 ul allantoic/80 ul of yeast. Samples 768-817). Incubation time was 4 h, followed by addition and incubation with substrates for an additional 10 min at 37° C.

[0021]FIG. 8 is a graph showing a comparison of time/response in two transactivation assays in response to estrogen (concentration 5 nM) using YRpE2 (CYC1 promoter based) and YRpE2SSA4-lacZ (heat shock promoter based) reporter vector at an ONPG (substrate) concentration of 0.2%. The incubation times with hormone were varied as shown prior to addition of substrates and subsequent substrate incubation time (15 minutes) at 30° C.

[0022]FIG. 9 shows the nucleic acid sequence of the CYC1-based estrogen inducible reporter YRpE2 (SEQ ID NO: 7). It comprises the E. coli replication origin and bacterial selection marker for Ampicillin resistance, the yeast 2 micron S. cerevisiae replicative origin, yeast selection marker URA3, and the E. coli beta-galactosidase gene which is operably linked to the CYC1 core promoter. The 2× estrogen response element (2×ERE) unit is operably linked to the CYC1 promoter in the upstream region.

[0023]FIG. 10 shows the nucleic acid sequence of the SSA4-based estrogen inducible reporter YRpE2SSA4-lacZ (SEQ ID NO: 8). It comprises the E. coli replication origin and bacterial selection marker for Ampicillin resistance, the yeast 2 micron S. cerevisiae replicative origin, the yeast selection marker URA3, and the E. coli beta-galactosidase gene which is operably linked to the SSA4 core promoter. The 2×ERE unit is operably linked to the SSA4 promoter in the upstream region.

[0024]FIG. 11 shows the nucleic acid sequence of the yeast expression vector for human estrogen receptor alpha—YEpE12-ERα (SEQ ID NO: 9). It comprises the E. coli replication origin and bacterial selection marker for Ampicillin resistance, the yeast 2 micron S. cerevisiae replicative origin, yeast selection marker TRP1, and a human estrogen receptor fused in frame with human ubiquitin which is operably linked to the yeast CUP1 promoter.

[0025]FIG. 12 shows the nucleic acid sequence of the yeast expression vector for the E. coli glucuronidase gene—pRS425-GPD-Ub-GUS (SEQ ID NO: 10). It comprises the E. coli replication origin and bacterial selection marker for Ampicillin resistance, the yeast 2 micron S. cerevisiae replicative origin, the yeast selection marker LEU2, and the E. coli beta-glucuronidase gene which is fused in frame with human ubiquitin which is operably linked to the yeast GPD promoter.

DETAILED DESCRIPTION OF THE INVENTION

[0026] In accordance with the present invention, compositions, methods and kits are provided for the accurate and efficient detection of biological target molecules. A yeast-based biosensor is disclosed to identify and characterize target molecules isolated from biological samples. In a preferred aspect of the invention, a gender sorting method is provided which enables pre-hatch sorting of female embryos from male embryos.

[0027] I. Definitions

[0028] The following definitions are provided to facilitate an understanding of the present invention.

[0029] As used herein, a “reporter gene” encodes a molecule whose expression may be assayed; such genes include, without limitation, β-galactosidase (LacZ), alkaline phosphatase, amino acid biosynthetic genes, e.g., the yeast LEU2, HIS3, or LYS2 genes, nucleic acid biosynthetic genes, e.g. URA3 or ADE2 genes, the chloramphenicol acetyltransferase (CAT) gene, green fluorescent protein (GFP), red fluorescent protein such as DsRd or any surface antigen gene for which specific antibodies are available. Additionally “reporter gene” may encompass any gene of interest whose expression may be detected. The term “reporters” may be used broadly to include systems where expression is detected based on ligand binding induced alterations in receptor structure. Such alterations in receptor structure may be assessed using a variety of methods well known to those of skill in the art, and include without limitation, assessing degradation, recycling, and molecular association rates of ligand bound receptor based on gain or loss of a detectable label. Such labels may be radioactive, fluorescent or chemiluminescent.

[0030] A “promoter” is a DNA sequence located proximal to the start of transcription at the 5′ end of an operably linked transcribed sequence. The promoter may contain one or more regulatory elements or modules that act together in coordinating and regulating transcription of the operably linked gene. An inducible promoter is a promoter that responds to the presence of different biochemical stimuli. Such promoters include, but are not limited, to the CUP1 promoter, heat shock promoters, galactose-inducible promoters, glycolytic promoters such as alcohol dehydrogenase (ADH) glyceraldehyde phosphate dehydrogenase (GPD) and the like.

[0031] “Operably linked” describes two macromolecular elements arranged such that modulating the activity of the first element induces an effect on the second element. In this manner, modulation of the activity of a promoter element may be used to alter and/or regulate the expression of an operably-linked coding sequence. For example, the transcription of a coding sequence that is operably linked to a promoter element is induced by factors that “activate” the promoter's activity; transcription of a coding sequence that is operably-linked to a promoter element is inhibited by factors that “repress” the promoter's activity. Thus, a promoter region is operably-linked to the coding sequence of a protein if transcription of such coding sequence activity is influenced by the activity of the promoter.

[0032] “Fusion construct” refers generally to recombinant genes which encode fusion proteins. Such fusion constructs may include operably linked nucleic acids isolated from two different genes.

[0033] A “fusion protein” is a hybrid protein, i.e., a protein that has been constructed to contain domains from at least two different proteins. An exemplary fusion protein, as described herein is a hybrid protein which possesses (a) a transcriptional regulatory domain from a transcriptional regulatory protein, or (b) a DNA binding domain from a DNA binding protein linked to a heterologous protein to be assayed for interaction. The structure of the fusion protein is such that the transcriptional regulatory domain and the DNA binding domain are arranged in a manner that allows both domains to be biologically active. The protein that is the source of the transcriptional regulatory domain is different from the protein that is the source of the DNA binding domain. In other words, the two domains are heterologous to each other.

[0034] The transcriptional regulatory domain of the fusion protein may either activate or repress transcription of target genes, depending on the native biological activity of the domain.

[0035] The term “fusion protein gene” refers to a DNA sequence that encodes a fusion protein. A fusion protein gene may further provide transcriptional and translational regulatory elements for the transcriptional and translational control thereof.

[0036] “Expression” is the process by which the information encoded within a gene is revealed. If the gene encodes a protein, expression involves both transcription of the DNA into mRNA, the processing of mRNA (if necessary) into a mature mRNA product, and translation of the mature mRNA into protein.

[0037] A nucleic acid molecule, such as a DNA or gene is said to be “capable of expressing” a polypeptide if the molecule contains the coding sequences for the polypeptide operably linked to expression control sequences which, in the appropriate host environment, facilitate transcription, processing and translation of the encoded genetic information into a protein product.

[0038] The phrase “consisting essentially of” when referring to a particular nucleotide or amino acid means a sequence having the properties of a given reference sequence. For example, when used in reference to an amino acid sequence, the phrase includes the sequence per se and molecular modifications that would not affect the basic and novel characteristics of the sequence.

[0039] As used herein, a “cloning vector” is any entity that is capable of delivering a nucleic acid sequence into a host cell for cloning purposes. Examples of cloning vectors include plasmids or phage genomes. A plasmid which replicates autonomously in a host cell is especially preferred. Alternatively, a nucleic acid molecule which stably integrates into the host cell's chromosomal DNA and is inherited by daughter cells may be employed. Optionally, such vectors include a number of endonuclease recognition sites to facilitate manipulation of the sequence in a controlled and targeted fashion. Cloning vectors of the invention may also comprise sequences conferring resistance to selection agents, often referred to herein as selectable marker genes. For example, “a marker gene” may be a gene which confers resistance to a specific antibiotic on a host cell.

[0040] As used herein, an “expression vector” is a vehicle or vector similar to the cloning vector but is especially designed to provide an environment that facilitates expression of the cloned gene product after transformation into the host. Such vectors contain regulatory elements for expression in prokaryotic and/or eukaryotic hosts as well as sequences conferring selection properties of cells containing the expression vector. Optionally, enhancer elements, termination sequences, tissue-specificity elements, and/or translational initiation and termination sites may be included.

[0041] A “host” refers to any organism or cell line that is the recipient of a cloning or expression vector. In preferred embodiments, the host of the invention is a yeast cell or a cultured animal cell such as a mammalian or insect cell. Especially preferred is the yeast host Saccharomyces cerevisiae.

[0042] A “transformed cell” is any cell into which (or into an ancestor of which) exogenous DNA has been introduced by means of recombinant DNA techniques.

[0043] “Ligands” are small compounds such as chemical molecules or small peptides that are able to bind to the target proteins (for example, the receptor heterodimers described herein). By interaction with a target protein, ligands change conformation of the protein and thereafter activate or inactivate the protein.

[0044] “Response elements” are specific DNA sequences located in promoters of inducible genes; such inducers may include chemicals, hormones, metals such as zinc, cadmium or copper, heat shock and transcription factors. Nuclear receptors in the form of homodimers, heterodimers or monomers bind specifically to DNA response elements to activate or repress transcription of the targeted genes in the presence or the absence of ligands for the nuclear receptors.

[0045] II. Methods and Compositions for Gender Sorting

[0046] Cost effective methods for sex segregation of avian eggs require a sex specific target which can be detected at 98% accuracy, at a rate of 10,000 to 20,000 eggs per hour, and can be offered to the poultry industry at a cost of less than 5 cents per egg sexed. Potential sex specific targets include: 1) differences in physiologic parameters such as heart; 11, 12); 2) presence of the W specific chromosome in females (13, 14, 15); 3) presence of anatomical differences such as gonads; and 4) chemical differences which may be present in the blood or extra-embryonic fluids of the avian embryo.

[0047] Methods that may be potentially useful for gender sorting are set forth in Table 1. TABLE 1 Comparison of LifeSensors Gender Sorting Sensors with Other Technologies Background Ease of Technology Speed Sensitivity Cost Interference Automation LifeSensor yes Yes yes no yes Biosensors no No yes no yes Electronic yes No yes yes yes Nose NIR yes No yes yes yes Spectrometry Ion Mobility yes No yes yes yes Spectroscopy Fluorescent yes Yes yes yes no Polarization Antibody yes Yes no no yes Based Technologies Photoacoustics yes No yes no yes Imprint yes No yes no yes Polymers Mass no Yes no no no Spectrometry Laser Induced yes No yes yes yes Fluorescent Spectrometry

[0048] Numerous analytical techniques to detect estradiol or other sex specific compounds were evaluated. As can be seen from Table 1 only the LifeSensors technology described herein meets the desired criteria of cost, sensitivity, speed, accuracy, safety and ease of application to a commercial hatchery environment.

[0049] Sex specific chemicals present in blood or extra-embryonic fluids provide optimal analytical targets for meeting the above criteria. Suitable chemical based targets are male or female-specific hormones. It is well established that male and female embryos exhibit significant differences in hormone levels in sera and in male or female gonadal tissue culture systems (16, 17, 18). The data provided in these studies suggested that differences in the estrogen levels of male and female embryos would be greater than differences in the testosterone levels.

[0050] Differences in sex hormone levels are also evident in the allantoic fluid. In 1983, Gill and coworkers reported the presence of estrone sulfate, estradiol-17β sulfate, estradiol-17α sulfate, estrone glucuronide, estradiol-17α glucuronide and estradiol-β glucuronide in pg/ml quantities in the allantoic fluid of female embryos but not in the allantoic fluid of male embryos. No estrogens were present in the amniotic fluid of either sex (19). The amniotic fluid is primarily maternally derived and acts as a nutrient source and a cushion from mechanical and thermal insults.

[0051] The present invention is directed to methods for detecting the presence of sex specific estrogen levels in the chorioallantoic fluid of avian eggs using a yeast-based genetic system. The use of chorioallantoic fluid is preferred over the use of either blood or amniotic fluid as the allantoic fluid is proximal to the outside of the egg and is not in direct contact with the fluid surrounding the embryo. The allantois is separated from the eggshell only by the inner and outer shell membranes and the chorioallantoic membrane. Although the allantoic sac containing the allantoic fluid encompasses the entire periphery of the embryonated egg, the allantoic fluid accumulates at the top and upper sides of the egg directly underneath the membranes overlying the air space. The accumulation at the top of the egg is due to gravity and displacement by the dense embryo and yolk sac.

[0052] The allantoic fluid is recognized as an excretory medium for the nitrogenous metabolites of the embryo (20). The allantoic fluid begins to form around Day 5 of incubation. It attains a maximum volume of 6.1 mls on Day 13 of incubation, wanes in volume as incubation continues due to moisture loss and fluid resorption but is still present in significant volumes (1 to 2 mls) on Day 18 of incubation (20). The accumulation of solids in the allantoic fluid is continuous throughout the developmental period. The presence of significant amounts of allantoic fluid, which is readily accessible, between Days 13 and 18 of incubation render the allantois a feasible target for detection of a sex specific chemical.

[0053] It should also be noted that the estrogen present in allantoic fluids is not an active form, as it exists in the form of conjugates with either glucuronides or sulfates. While immunoassay is available for detecting conjugated estrogen levels, the method is not extremely sensitive nor, more importantly, cost-effective.

[0054] The presence of estrogens in the allantoic fluid of Day 17 embryos has been further investigated in efforts to assess the reliability of estrogens as a sex specific chemical marker. The estradiol levels in the allantoic fluid of male and female Day 17 broiler chicken embryos were measured using a commercially available RIA kit (Diagnostic Products, Los Angeles, Calif.).

[0055] The estradiol level in the allantoic fluid of male embryos was either non-detectable or less than 42 pg/ml. The estradiol level in the allantoic fluid of female embryos was between 184 and 830 pg/ml, at least four times higher than the levels detected in male embryos. These data indicate that estrogen conjugates can be used to segregate female from male embryos.

[0056] The presence of testosterone in the allantoic fluid has also been investigated as androgens may interfere with analysis of estradiol due to similarity in molecular structures. Studies have shown that testosterone levels were undetectable in the allantoic fluid of Day 17 broiler embryos using a commercial RIA kit (Diagnostic Products, Los Angeles, Calif.).

[0057] Studies were also conducted to assess the optimal period of embryonic incubation for estradiol detection using the analytical methods described herein. Estradiol was initially detected by our methods on Day 13 of incubation and coincided with reports by Gill and coworkers (19). As shown herein, estrogen levels peaked at Day 17 of incubation.

[0058] In accordance with the present invention, a yeast-based genetic system and methods of use, thereof are provided to facilitate gender sorting in poultry. The methods provided herein enable the rapid and efficient sorting of eggs based on the presence of sex hormones in allantoic fluid.

[0059] II. Preparation of Nucleic Acid Molecules Encoding the Proteins of the Invention and Uses Thereof in Assay Methods and Kits

[0060] A. Nucleic Acid Molecules

[0061] Nucleic acid molecules encoding the expression vectors of the invention may be prepared by two general methods: (1) They may be synthesized from appropriate chemical starting materials, or (2) they may be isolated from biological sources. Both methods utilize protocols well known in the art.

[0062] The availability of nucleotide sequence information, for the estrogen receptor, as well as for secretory signals from alpha-mating factor or yeast SUC2 gene facilitates synthesis of DNA constructs containing such sequences. Synthetic oligonucleotides may be prepared by the phosphoramadite method employed in the Applied Biosystems 38A DNA Synthesizer or similar devices. The resultant construct may be purified according to methods known in the art, such as high performance liquid chromatography (HPLC). Long, double-stranded polynucleotides, such as a DNA molecule encoding a construct of the present invention, must be synthesized in stages due to the size limitations inherent in current oligonucleotide synthetic methods. Thus, for example, a 3 kilobase double-stranded molecule may be synthesized as several smaller segments of appropriate complementarity. Complementary segments thus produced may be ligated such that each segment possesses appropriate cohesive termini for attachment of an adjacent segment. Adjacent segments may be ligated by annealing cohesive termini in the presence of DNA ligase to construct the entire 3 kilobase double-stranded molecule. A synthetic DNA molecule so constructed may then be cloned and amplified in an appropriate vector. In alternative embodiments of the invention, the human estrogen receptor α (referred to herein as “estrogen receptor”), reporter gene and E. coli gene for expression of glucuronidase can be substituted with similar genes from other biological sources. Suitable candidate genes for such substitution include, without limitation, estrogen receptor β which also has high affinity for the hormone and does mediate transactivation in eukaryotic cells in response to 17β estradiol. In addition, one can replace human estrogen receptor with a homologous receptor molecule from mouse or other higher eukaryotic estrogen receptors. The E. coli beta-glucuronidase gene can be replaced with a snail gene that expresses glucuronidase, or any other glucuronidases that can cleave the 17β estradiol glucuronides. For example, the Lactobacillus gasseri gusA gene with a pH optima of 5 also provides a suitable candidate GUS gene (Russell and Klaenhammer, 2001). Since the pH of extracellular yeast media is acidic, this enzyme is well suited for use in the gender sorting sensor as an extra step to adjust the pH can be omitted.

[0063] Estrogen conjugates are cleaved by β-glucuronidases to produce 17β estradiol. The pure estrogen molecule binds to the resident estrogen receptor to transactivate a reporter gene. In accordance with the present invention methods for assessing estrogen levels in allantoic, or amniotic fluid or any other biological or chemical estrogens and their ability to transactivate the reporter genes described herein are provided. The constructs containing the estrogen receptor encoding sequences described herein may be substituted either with mutated (modified or altered receptor) or a receptor from another species.

[0064] Similarly, the glucuronidase enzyme of the invention may be derived from different species. The E. coli β-glucuronidase has been used in the studies described herein. However, β-glucuronidases from rat or human may have altered properties that may make them more robust and efficient than the E. coli glucuronidase. The use of glucuronidase from Lactobacillus gusA (GenBank Accession number: AF305888) is also encompassed within the scope of the present invention. In addition to estrogen glucuronides, biological fluids may contain other forms of modified estrogens such as estrogen sulfates. Under these circumstances appropriate de-conjugating enzymes such as sulfatases can be employed to convert the estrogen conjugate into 17 β estradiol. Thus, in this situation, glucuronidases can be replaced with sulfatases.

[0065] Nucleic acid sequences encoding the components of the expression plasmids of the invention may be isolated from appropriate biological sources using methods known in the art. For example, RNA isolated from a mammalian or insect cell may be used as a suitable starting material for the generation of cDNA molecules encoding the different receptor proteins.

[0066] In accordance with the present invention, nucleic acids having the appropriate level of sequence homology with the protein coding region of the DNA molecules of the present invention may be identified by using hybridization and washing conditions of appropriate stringency. For example, hybridizations may be performed, using a hybridization solution comprising, for example, 5×SSC, 5× Denhardt's reagent, 1.0% SDS, 100 mg/ml denatured, fragmented salmon sperm DNA, 0.05% sodium pyrophosphate and up to 50% formamide. Hybridization is carried out at 37-42° C. for at least six hours. Following hybridization, filters are washed as follows: (1) 5 minutes at room temperature in 2×SSC and 1% SDS; (2) 15 minutes at room temperature in 2×SSC and 0.1% SDS; (3) 30 minutes-l hour at 37° C. in 1×SSC and 1% SDS; (4) 2 hours at 42-65° C. in 1×SSC and 1% SDS, changing the solution every 30 minutes.

[0067] One common formula for calculating the stringency conditions required to achieve hybridization between nucleic acid molecules of a specified sequence homology is as follows (21):

T _(m)=81.5° C.+16.6 Log [Na+]+0.41(% G+C)−0.63(% formamide)−600/#bp in duplex

[0068] As an illustration of the above formula, using [Na+]=[0.368] and 50% formamide, with GC content of 42% and an average probe size of 200 bases, the T_(m) is 57° C. The T_(m) of a DNA duplex decreases by 1-1.5° C. with every 1% decrease in homology. Thus, targets with greater than about 75% sequence identity would be observed using a hybridization temperature of 42° C. Such a sequence would be considered substantially homologous to the sequences of the present invention.

[0069] Nucleic acids encoding the fusion proteins of the invention may be maintained as DNA in any convenient cloning vector. In one embodiment, clones are maintained in plasmid cloning/expression vectors, such as pRS plasmids series (27), or YEpE12 derivative plasmids (26, 28). pBluescript plasmids (Stratagene, La Jolla, Calif.) or recombinant baculovirus transfer vector plasmids, such as pFastBac vectors (Gibco-BRL, Gaithersburg, Md.) that are propagated in insect and E. coli host cells, may also be employed.

[0070] The nucleic acids of the invention may also be used as starting materials for the generation of sequence variants or truncation mutants of the nucleic acids of the invention using any number of synthetic and molecular biologic procedures well known in the art including, but not limited to, truncation at available restriction sites and site-directed mutagenesis techniques. Particular mutations may give rise to receptor proteins with altered characteristics such as increased or decreased ligand binding activity.

[0071] B. Fusion Proteins

[0072] In one embodiment of the invention, the estrogen receptors of the invention are expressed in yeast as ubiquitin fusion proteins. Ubiquitin fusion enhances but is not necessary for protein expression in yeast. After translation of recombinant proteins, the 76 amino acids of ubiquitin sequence in the N-terminus are cleaved by the host ubiquitin pathway and native proteins are released. It is widely known that the presence of the ubiquitin sequence improves the expression of proteins of interest in yeast and E. coli (26, 29).

[0073] Attachment of SUMO, a 101 amino acid protein, to the N-terminus of GUS also enhances the expression and extracellular secretion of the protein into the media. SUMO is a homologue of ubiquitin that is conjugated to other proteins via the epsilon amino groups of lysine (Yeh et al 2000, Mahajan et al 1997). The Smt3 gene in yeast encodes for SUMO (Li and Hochstrasser 2000). Similar to the case with ubiquitin conjugation and de-conjugation to other proteins, SUMO can be cleaved from the fusion protein by SUMO specific proteases (Li and Hochstrasser 2000, Kim et al 2000). Therefore, SUMO-fusion proteins can also be expressed and cleaved in eukaryotic and prokaryotic cells. Since SUMO protein or SUMO enzymes are absent in prokaryotes, sumolated proteins expressed in E. coli are not cleaved in the absence of SUMO specific hydrolase or protease. In eukaryotic cells, such as yeast, a SUMO-GUS fusion is cleaved by cellular SUMO specific hydrolases (Suzuki et al 1999, Kim et al 2000, Li and Hochstrasser 2000).

[0074] The glucuronidase enzymes of the invention are expressed in yeast after attachment of secretory signals and as ubiquitin fusion protein(s) as well. The attachment of the secretory signals in the N-terminal region of glucuronidase or ubiquitin facilitates extracellular secretion of the enzyme following translation. A wide variety of secretion signal sequences are available, including but not limited to, the N-terminus of alpha factor or SUC2. FIG. 5 shows an exemplary plasmid that was robust in secreting E. coli GUS in yeast. Similar plasmids may be generated containing glucuronidase genes from other species, under different secretory signals using different promoters and different hosts to produce active GUS that can cleave the estrogen-glucuronides conjugates.

[0075] In a preferred embodiment of the invention, nucleic acid sequences encoding the N-terminus of glucuronidase were operably linked at the C-terminus to a ubiquitin gene. The presence of the ubiquitin moiety at the N-terminus of glucuronidase facilitated and enhanced secretion of the enzyme. See Table 8.

[0076] In an alternative embodiment of the invention, the fusion proteins may be prepared using in vitro expression methods known in the art. In this fashion, glucuronidase may be supplied exogenously to the transactivating system of the invention. For example, a cDNA or gene may be cloned into an appropriate in vitro transcription vector, such as pSP64 or pSP65 for in vitro RNA synthesis, followed by cell-free translation of the RNA in a suitable cell-free translation system, such as extracts of wheat germ, rabbit reticulocytes or HeLa cells. In vitro transcription and translation systems are commercially available (e.g., Promega Biotech, Madison, Wis.; Gibco-BRL, Gaithersburg, Md.).

[0077] C. Assay Methods and Kits:

[0078] In yet another embodiment of the invention, assays are provided wherein intact cells expressing the proteins of the invention are contacted with biological samples containing molecules suspected of affecting the intracellular activity of the estrogen receptor. After a suitable time period, the effects of such agents on estrogen dependent transactivation activity are measured. Such activity may be quantitated in any number of ways. For example, such cell systems may utilize a reporter system in which the production of the reporter signal is dependent on estrogen dependent transactivation. Numerous reporters may serve equally well in this application including but not limited to, beta-galactosidase, alkaline phosphatase, fluorescent green protein and the like. Furthermore, the methods of the invention may be practiced in bacterial, fungal, insect, avian, mammalian or plant cells. However, yeast-based cell systems are preferred due to low cost and the feasibility of growing yeast cells in plastic devices.

[0079] Assays for screening estrogen-containing biological fluid samples are also provided. Assays involving the cell-based systems of the invention may be formatted in any number of configurations. Particularly useful for evaluating large numbers of agents and materials are high throughput screening formats. Traditionally such assays were typically formatted in 96 well plates. However, 384, 864 and 1536 well plates or a custom designed plate may be used in such high throughput assay systems. These systems are often automated using robotics technologies to allow manipulation and processing of large numbers of samples.

[0080] According to another aspect of the invention, antibodies immunologically specific for various proteins may be used in the gender sorting assays of the present invention. Such antibodies may be monoclonal or polyclonal. Additionally, antibody fragments having binding affinity for various proteins may also be used to advantage in the gender sorting assays. Such antibody fragments comprise Fab, Fab′, F(ab′)2, F(v) and Sfv generated recombinantly. Such antibodies or fragments thereof may be used to advantage in the methods and kits of the present invention as described below.

[0081] In another aspect, the invention includes kits to facilitate the use of the compositions and methods disclosed herein. Exemplary kits include the expression plasmids and yeast strains of the invention, and/or variants thereof. Also provided are beta-glucoronidase enzymes or sulfatase enzymes or plasmids encoding the same. Protocols for use of the compositions of the invention for the particular application and the necessary reagents to carry out the application are also provided. Such reagents may include, but not be limited to, buffers, solvents, media and solutions, substrates and cofactors, vectors and host cells, and detection or reporter reagents. Accessory items may include vials, vessels, reaction chambers and instruction sheets.

[0082] The following protocols are provided to facilitate construction of the expression plasmids for use in the methods and kits of the present invention.

[0083] Yeast Media, Strains and Plasmids.

[0084] Standard yeast media were prepared as described (22). YPD composed of Yeast Extract (20 grams per liter), Peptone (20 g/liter), Dextrose (20 g/Liter) is preferred for use in the invention as most yeast strains grow in this media. Yeast selective media (complete-drop out) used to maintain plasmids composed of yeast nitrogen base 1.7 g/L, ammonium sulfate 5 g/L, dextrose 20 g/L, different amino acids and other supplements were added depending on the requirements of the particular yeast strain. For example if the yeast plasmid contains LEU2 marker, the leucine is dropped out from the media in order to select the plasmid.

[0085] Yeast strains suitable for use in the present invention include the yeast strain Y4727, snq2::Δ pdr5::kanMX: Matα his3-Δ200 leu2-Δ0 lys2-Δ0 met5-Δ0 trp1-A63 ura3-Δ0 snq2::Δ pdr5::kanMX (original strain Y4747 was a gift from Dr. Jeff Boeke) BJ1991 Mat α prb1-1122 pep4-3 leu2 trp1 ura3-52 gal2 (a gift from Dr. Beth Jones), and RS188: MATa leu2-3,112 trp1-1 ura3-1 ade2-1 his3-11,15 can1-100,

[0086] Construction of the β-Glucuronidase Expression Plasmids.

[0087] A series of yeast expression plasmids have been constructed, all of which are yeast-E. coli multicopy shuttle plasmids, containing LEU2 as a yeast transformation marker. See Table 8. FIG. 5 depicts an exemplary plasmid of the invention that is suitable for GUS production in our assay—plasmid pRS425-GPDp-UB-GUS is comprised of plasmid pRS425 (23) E. coli GUS from reference 24, human ubiquitin (amplified from plasmid YEpE12; Graumann et al., 1996) and S. cerevisiae GPD promoter (plasmid pRS423GPDp was described in Mumberg et al., 1995). See FIG. 4 herein. However, as described herein, additional plasmids for Gus expression were constructed and tested. Those plasmids include pRS425-ADH1p-GUS, pRS425-ADH1p-α-factor-GUS1, pRS425-GPDp-Ub-GUS1, pRS425-GPDp-Ub-α-factor-GUS1, pRS425-GPDp-α-factor-Ub(pro)-GUS1, pRS425-GPDp-α-factor-Ub(met)-GUS1 and pRS425-CUP1p-Ub-GUS1. pRS425-GUS1 was produced by cloning the XhoI-SacI fragment (containing E. coli β-Glucuronidase from plasmid pGUS1 (24) into the XhoI-SacI sites of plasmid pRS425 (23). The next construction involved addition of a promoter, and giving rise to plasmid pRS425-ADH1p-GUS. An XhoI-HindIII fragment containing the ADH1 promoter was inserted into the XhoI-HindIII sites of the plasmid pRS425-GUS. The ADH1 promoter XhoI-HindIII fragment was cloned using polymerase chain reaction (PCR), followed by amplification of the ADH1 promoter from the plasmid pGRIP1 (25). The following primers were used to amplify the full length ADH1 promoter: ADH1-XhoI: 5′-gctcgagagcacagatgcttcgttg-3′ (SEQ ID NO: 1) and ADH1-HindIII: 5′-gcaaagcttggagttgattgtatgc-3′ (SEQ ID NO: 2). The underlining indicates the nucleotide sequence of the XhoI and HindIII restriction sites. PCR of the DNA fragment involved amplification in 30 cycles (96° C.—30 sec., 54° C.—1 min. and 72° C.—3 min.) using high replication fidelity Deep Vent Polymerase (New England Biolabs). The PCR product was then digested with XhoI and HindIII, and subsequently cloned into the XhoI-HindIII sites of pRS425-GUS. pRS425-ADH1p-α-factor-GUS, comprises a secretory signal fused in frame with the N-terminus open reading frame of GUS. Nucleic acid sequences encoding the alpha factor signal from plasmid pPIC9 (Invitrogen) were amplified by PCR using the primers alpha-HindII (forward): 5′-acc aag ctt att cga agg atc caa acg atg ag-3′ (SEQ ID NO: 3) and alpha-HindIII (reverse): 5′-gcc aag ctt gga gcc tct ctt ttc tcg aga g-3′ (SEQ ID NO: 4). Again the underlining indicates the nucleotide sequence of the restriction HindIII site. The PCR product was digested with Hind III and subsequently cloned into the Hind III site of pRS425-ADH1p-GUS, in frame with the open reading frame of GUS. Similarly the plasmids pRS425-GPDp-Ub-GUS1, pRS425-GPDp-Ub-α-factor-GUS1, pRS425-GPDp-α-factor-Ub(pro)-GUS1, pRS425-GPDp-α-factor-Ub(met)-GUS1 were constructed using plasmids pRS425-GPDp as an original vector. The ubiquitin coding DNA fragment was amplified from YEpE12 (Graumann et al., 1996). The plasmid pRS425-CUP1p-Ub-GUS1 was constructed by replacing the GPDp-Ub fragment from plamsid pRS425-GPDp-Ub-GUS1 with CUP1p-Ub fragment derived from plasmid pRS425-CUP1-Ub-CfUSP (Tran et al., 2001).

[0088] Yeast Transformation

[0089] Briefly, yeast cells were cultured in 5 mL of YPD liquid medium overnight at 30° C. The cell culture was diluted 1:20 in YPD media and further grown until cell density reached an O.D of 0.6. at OD₆₀₀. The cells were pelleted by centrifugation and washed with 10 mL of 10 mM Tris-Hcl pH 8.00, 1 mM EDTA (TE) containing 0.1M lithium acetate. Pelleted cells were resuspended in 10 mL of TE plus 0.1M lithium acetate and incubated at 30° C. for 1 hour. Cells were collected and resuspended in 0.5 mL of TE plus 0.1M lithium acetate. Aliquots of cells (50 μL), were incubated for 15 minutes at 30° C. with 1-2 μg plasmid DNA in the presence of 5 μg of denatured salmon sperm DNA as DNA carrier. In the case of co-transformation, the indicated plasmids were added simultaneously. 50% polyethyleneglycol of molecular weight 4000, diluted in TE, was added to a final concentration of 35%. DMSO was added to the transformation solution simultaneously to a final concentration 3%. The samples were mixed well by vortexing and incubated for an additional 30 minutes at 30° C. The cell mixture was then heated for 15 minutes at 42° C. Cells were collected and plated onto appropriate yeast selective media. Transformants of 4 plasmids were selected on complete media without tryptophan, uracil, leucine or histidine.

[0090] A. Accurate and Efficient Estrogen Transactivation as assessed by β-Galactosidase Activity Assays using o-nitrophenyl-beta-D-galactopyranoside (ONPG) as a Substrate.

[0091] Yeast cells containing yeast expression plasmids for human estrogen receptor and estrogen-inducible reporter gene were grown overnight in selective liquid media at 30° C. and were diluted in pre-warmed liquid selective media to 0.1 at OD₆₀₀ (OD_(culture)). See Lyttle et al., 1992. 100 μl of the cell culture was spiked into each well of a 96-well microtiter plate. Ligand (2 μl diluted in DMSO) was added to each well to produce a final concentration of 2% DMSO. As a control, 2 μl of DMSO were also added to additional test wells. The final concentration of 17-β estradiol ranged from 100 pM to 10 nM.

[0092] The cells were incubated in the presence of the ligand in a shaker at 30° C. After 4 hours of incubation, 100 μl of 2×“Z” Sarcosine-ONPG buffer (120 mM Na₂HPO₄, 80 mM NaH₂PO₄, 20 mM KCl, 2 mM MgSO₄, 100 mM beta-mercaptoethanol (Sigma), pH 7.0, 0.4% lauroyl sarcosine (Sigma), 4 mg/mL ONPG (Diagnostic Chemicals limited) was added to each well and the plate was further incubated at 37° C. The 2×“Z” Sarcosine-ONPG buffer was freshly prepared or stored at −20° C. prior to use. After incubation at 37° C. for 1 hour, the reaction was stopped by adding 100 μL of quenching solution 0.5 M Na₂CO₃ and the OD₄₀₅ (OD_(reaction)) was determined. Beta-galactosidase activity was measured in a micro plate reader (Biotek) at a wave length of 405-450 nanometers. The relative activity of β-galactosidase was calculated as follows:

(1000×OD_(reaction))/(t_(incubation)×OD_(culture)). “Z” Buffer  16.1 g Na2HPO4 7H2O (60 mM)  5.5 g NaH2PO4 H2O (40 mM)  0.75 g KCl (10 mM) 0.246 g MgSO4 7H2O (1 mM)  2.7 ml beta-mercaptoethanol (50 mM)

[0093] B. Accurate and Efficient Gender Sorting of Allantoic fluids, using Exogenously Supplied GUS-ONPG as β-Galactosidase Substrate.

[0094] The present assay is similar to the estrogen-induced transactivation assay described above. However, in this assay, estrogen-conjugates present in allantoic fluids from 17-day incubated eggs are tested. Unless present at very high concentrations (approximately 10 micromolar (μM)) estrogen conjugates themselves do not induce receptor transactivation because of the low affinity of the estrogen receptor for such conjugates. This concentration greatly exceeds that present in allantoic fluids which is approximately 200 pM. Thus, the present assay consists of two steps: a) release of estrogen from conjugated forms present in allantoic fluids by Glucuronidase (from snail juice, Sigma, cat. #G7017); and b) assessing the released hormone for its ability to stimulate production of the reporter gene in the yeast based transactivation assay.

[0095] Initially, allantoic fluids are exposed to beta-glucuronidase. 75 ul of each allantoic fluid sample was placed into a microcentrifuge tube. To each tube 40 ul of 0.2 M Acetate Buffer pH 4.6 was added. 20 ul of beta-glucuronidase from snail (Sigma cat. #G7017) was added and the entire reaction mixed well. The reactions were incubated at 37° C. for 1 hour. Beta-glucuronidase will cleave the estrogen-conjugates in allantoic fluids thereby releasing free estrogen. In order to inactivate the GUS enzymes, the reactions were heated at 95° C. for 5 minutes. The GUS heat inactivation step is required when snail GUS is used as the snail GUS contains other enzymes that also cleave ONPG. Of note, when purified E. coli GUS was used (Sigma #G-7396), the GUS inactivation step was not required because E. coli GUS does not interfere with ONPG cleavage. The released estrogen was utilized in a transactivation assay in yeast. Yeast cells containing yeast expression plasmids for human estrogen receptor (YEpE12) and an estrogen-inducible reporter gene (YRpE2) were grown overnight in selective liquid media at 30° C. and diluted in pre-warmed liquid selective media to a density of 0.1 at OD₆₀₀ (OD_(culture)). 100 μl of cell culture was spiked into each well of a 96-well microtiter plate. Four to eight μl of the GUS-treated allantoic fluids were added to the yeast cell suspension. The cells were incubated in the presence of the ligand in a shaker at 30° C. After 4 hours of incubation, 100 μl of 2×“Z” Sarcosine-ONPG buffer (120 mM Na₂HPO₄, 80 mM NaH₂PO₄, 20 mM KCl, 2 mM MgSO₄, 100 mM beta-mercaptoethanol (Sigma), pH 7.0, 0.4% lauroyl sarcosine (Sigma), 4 mg/mL ONPG (Diagnostic Chemicals limited) was added to each well and the plate was further incubated at 37° C. The 2×“Z” Sarcosine-ONPG buffer was freshly prepared or stored at −20° C. prior to use. After incubation at 37° C. for 1 hour, the reaction was stopped by adding 100 μL of quenching solution 0.5 M Na₂CO₃ and the OD₄₀₅ (OD_(reaction)) 25 determined. Beta-galactosidase activity was measured in a micro plate reader (Biotek) at a wave length of 405-450 nanometers (nm) as described above.

[0096] Preferably, the estrogen source for analysis is obtained from the allantoic fluid of the egg that is treated with beta-glucuronidase enzyme. β-glucuronidase may be exogenously supplied or endogenously produced from yeast cells harboring a Gus expression plasmid.

[0097] C. Accurate and Efficient Gender Sorting using Estrogen-Conjugate Containing Allantoic Fluids, Endogenous GUS-ONPG as β-Galactosidase Substrate.

[0098] Yeast cells BJ1991 containing yeast expression plasmids for human estrogen receptor (YEpE12; See Graumann et al., 1996) and estrogen-inducible reporter gene (YRpE2) and a vector for GUS expression (pRS425-GPDp-Ub-GUS1) were able to grow in standard synthetic minimum medium (20 g glucose, 5 g ammonium sulfate, and 1.7 g yeast nitrogen base per liter). Notably, the optimal pH for E. coli GUS activity is 6.8 while yeast standard synthetic medium has a pH 5.2. Yeast cells were grown overnight in special selective liquid media (SSLM, standard liquid media mix with 10×NEB4 buffer in 9:1 ratio, pH 6.4) at 30° C. and were diluted in pre-warmed SSLM to 0.2 at OD₆₀₀ (OD_(culture)). 80 μl. of the cell culture was spiked to each well of a 96-well microtiter plate. 20 ul of allantoic fluid from 17-day incubated eggs were added to the wells. As controls, 20 μl of H₂O or 17-β estradiol (1 nM) were added to additional test wells. The cells were incubated in the presence of the ligand in a shaker at 30° C. After 4 hours of incubation, 100 μl of 2×“Z” Sarcosine-ONPG buffer (120 mM Na₂HPO₄, 80 mM NaH₂PO₄, 20 mM KCl, 2 mM MgSO₄, 100 mM beta-mercaptoethanol (Sigma), pH 7.0, 0.4% lauroyl sarcosine (Sigma), 4 mg/mL ONPG (Diagnostic Chemicals limited] was added to each well and the plate was further incubated at 37° C. for 1 hour. The 2×“Z” Sarcosine-ONPG buffer was freshly prepared or stored at −20° C. prior to use. After incubation at 37° C. for 1 hour, the reaction was stopped by adding 100 μL of quenching solution 0.5 M Na₂CO₃ and the OD₄₀₅ (OD_(reaction)) determined. Beta-galactosidase activity was measured in a micro plate reader (Biotek) at a wave length of 405-450 nanometers as previously described. NEB4 (10 × Buffer) 500 mM Potassium acetate 200 mM Tris-Acetate 100 mM magnesium acetate pH 7.

[0099] For some applications, it may be advantageous to use MP medium, which can be packed as a dry powder, as a substitute for SSLM (standard liquid medium mix with 10×NEB4 buffer in 9:1 ratio, pH 6.4). MP is combination of standard synthetic medium with potassium acetate at a final concentration of 50 mM. MP medium has a similar buffering capacity to that of SSLM medium, but it may be prepared and shipped as a dry powder.

[0100] D. Accurate and Efficient Gender Sorting of Allantoic Fluids, using Exogenously Supplied E. coli GUS Added Directly into the Assay Media, YRpE2SSA4-lacz as a Reporter and ONPG as the β-Galactosidase Substrate.

[0101] For applications in which the gender sorting assays of the present invention are used in large scale operations, the following modifications may be used to advantage. These modifications render the gender sorting assays even more robust and, therefore, amenable to high throughput processes. Accordingly, an additional reporter has been constructed which utilizes the rapid response, inducible heat shock promoter SSA4. The present inventors have also discovered that the use of MP medium, which can be packed as a dry powder, eliminates the need for supplementary beta-mercaptoethanol in the “Z” buffer (see below). The modified assay is similar to the estrogen-induced transactivation assay described above. In this assay, however, estrogen-conjugates present in allantoic fluids from Day 17 incubated eggs were tested.

[0102] Briefly, yeast strain BJ1991 comprising yeast expression plasmids expressing the human estrogen receptor (YEpE12) and an estrogen-inducible reporter gene (YRpE2SSA4-lacZ; FIG. 3B) were grown overnight in MP selective liquid media at 30° C., after which the overnight cultures were diluted in MP liquid selective media to an OD₆₀₀ of 0.2. Purified E. coli GUS (Sigma #G-7396) was added to the diluted yeast cell culture to a final concentration 1 unit per 100 μl. Eighty microliters of the yeast cell culture was spiked to each well of a 96-well microtiter plate. To each well, 20 μl of allantoic fluid from Day 17 incubated eggs were added. The yeast cell/allantoic fluid mixture was incubated at 30° C. for 1 hour, after which 100 μl of 2×“Z” Sarcosine-ONPG buffer without beta-mercaptoethanol (120 mM Na₂HPO₄, 80 mM NaH₂PO₄, 20 mM KCl, 2 mM MgSO₄, pH 7.0, 0.4% lauroyl sarcosine, 4 mg/mL ONPG) was added to each well and the plate was further incubated at 37° C. The 2×“Z” Sarcosine-ONPG buffer was freshly prepared or stored at −20° C. prior to use. After incubation at 30° C. for 30 minutes reaction colors were determined using a CCD camera to measure the number of pixels in each wells.

EXAMPLE I 17 β-estradiol Dependent Transactivation in Yeast Cells Expressing Estrogen Receptor

[0103] In accordance with the present invention, compositions and methods are provided for pre-hatch gender sorting in avian eggs. It has previously been demonstrated that the concentration levels of estrogens in the conjugated form is higher in female allantoic fluids as compared to male allantoic fluids (19) and FIG. 1. Thus, this fluid provides ideal starting material for gender sorting of chicken eggs which is based on estrogen concentration levels.

[0104] Using several classic methods (radioimmunoassays, etc), one can determine the concentration of estrogens in different biological samples. However, these methods are cumbersome, expensive and not readily adaptable to high throughput formats. The present method described and claimed herein provides robustness, cost-effectiveness and is 100% accurate, thereby satisfying industrial requirements.

[0105] As shown in Table 2, the transactivation system of the invention responds only to a specific ligand for the estrogen receptor, 17-β estradiol. Other ligands (Table 2) have very little transactivating activity. Both estrone sulfate and estrone glucuronide have very little to no effect on estrogen transactivation. Furthermore, the yeast transactivation assay is 100-fold more sensitive to 17-β estradiol when compared to mammalian cell assays and no transactivation was observed with the indicated concentration of estrogen glucuronides. The data in the following Table 2 demonstrate that the human estrogen receptor-driven yeast sensor is extremely sensitive and selective for 17-β Estradiol. TABLE 2 Specificity and selectivity of estrogen sensor. Cross-activity was determined at concentration of 50% maximum potency. Compound Percent Cross Reactivity* 17-β Estradiol 100 Estrone 8 16-Hydroxyestrone 4.0 Estriol 0.4 Estrone Sulfate <0.25 Estrone Glucuronide <0.25 2-Methoxyestrone <0.25 4-Hydroxytamoxifen <0.25 Androstenediol 0.08 Testosterone <0.05 Dihydrotestosterone <0.05 Mesterolone <0.05 Dehydroepiandrosterone <0.05 Androstenedione <0.05 Androsterone <0.05 Progesterone <0.025 17-Hydroxyprogestreone <0.025 Danasol <0.025 Corticosterone <0.025 Hydrocortisone <0.025

EXAMPLE II Treatment of Estrogen Conjugates from Allantoic Fluids with Exogenous GUS followed by Yeast Transactivation Assay

[0106] A two step treatment of allantoic fluids with exogenous GUS [snail juice GUS (Sigma #G-7017) or bacterial Gus (Sigma #G-7896)] and subsequent use of a yeast estrogen sensor to estimate the level 17β-estradiol released from the allantoic estrogen conjugates is described. A schematic diagram of the assay is shown in FIGS. 2A-2C. The yeast strain used in the present example has been transformed with a yeast expression vector for human estrogen receptor and an estrogen-inducible reporter gene. As described above, in the absence of GUS treatment, allantoic fluids do not induce transactivation of the estrogen biosensor. Accordingly, allantoic fluids were treated with Glucuronidase isolated from snail juice (Sigma cat#G-7017) or bacterial GUS (Sigma Cat #G 7896). Treatment of allantoic fluids with snail GUS has been described above. Treatment of allantoic fluids with bacterial GUS is described hereinbelow.

[0107] GUS Treatment

[0108] Removal of glucuronides was performed in a total reaction volume of 100 μL, containing 10 μL of NEB 3 buffer 10× (100 mM NaCl, 50 mM Tris-HCl, 10 mM MgCl2, 1 mM dithiothretol, pH 7.9) or NEB4 buffer (50 mM potassium acetate 20 mM Tris-Acetate, 10 mM magnesium acetate, pH 7), 50 μL of allantoic fluids, and 10 units of bacterial GUS enzyme. The final concentration of the estrogen-glucuronide conjugates was 1 μM. The reaction mixture was incubated at 37° C. for 1 hour; and stopped by heating at 95° C. for 5 minutes to inactivate the enzyme. After treatment with GUS enzyme, the 17β-estradiol is released from the conjugate. The reporter assays are then performed as follows:

[0109] 1. 4 to 8 μL of each GUS treated allantoic fluid reaction mix was spiked into the wells of a 96 well microplate.

[0110] 2. To each well 100 μL of yeast estrogen sensor cell suspension was added, incubated at 30° C. as described above in Example I.

[0111] 3. The activity of the reporter gene (beta-galactosidase) was measured by adding 100 μl of 2×“Z”-ONPG as described above.

[0112] Of note, purified glucuronidase isolated from E. coli (Sigma #G-7896), does not interfere with ONPG, and the heating step described in the previous example is required only when using snail juice GUS. Purified glucuronidase from E. coli was able to cleave estrogen conjugates with equal efficiency. However, the optimal pH of the reactions catalyzed by snail juice Gus and E. coli derived Gus differ significantly (pH 5.2 for snail juice and pH 6.8 for bacterial GUS). The data presented in Table 3 shows a comparison of conventional dissection of bird embryos for sex determination and the yeast based transactivation system of the invention using Gus treated estrogen conjugates isolated from allantoic fluids. As shown in Table 3, there is 100% agreement in sex determination using the two methods. TABLE 3 Ability to gender sort allantoic fluid from Day 17 Hyaline layer embryos Optical Gender Density M .328 M .332 M .338 F 1.204 F 2.261 M .352 F 2.664 F 2.424 F 2.300 F 2.057

[0113] The experimental protocol described above employs only 4 μL of allantoic fluid. The data shown in table 3 are based on the determination of estrogen levels after allantoic fluids from hyaline layer embryos were treated with snail β-glucuronidase and subsequently tested in β-galactosidase reporter assays as described above. Among 10 allantoic fluid samples tested, four of the allantoic fluids were from male embryos while six of the allantoic fluid samples were collected from female embryos. As shown herein, that female allantoic fluid samples showed activity equivalent to 4-8 nM estradiol in the undiluted allantoic fluid after β-glucuronidase treatment. The signal elicited by the allantoic fluid samples collected from male embryos was equal to that of the buffer control.

[0114] Sex Specific Signal Readily Determined Regardless of Egg Size or Flock Age from which Chicken Eggs are Derived.

[0115] Allantoic fluid samples were collected from eggs of a young flock, a flock in peak production and an old flock. The eggs from the young flock were small in size while the eggs from the old flock were large. The yeast-based estrogen sensor described above was used to determine the level of 17-β estradiol. The sex of the embryos was identified at 100% accuracy regardless of flock age. See Table 4. TABLE 4 Effect of broiler flock age on ability to gender sort allantoic fluid Flock Age Sex by Optical (Weeks in ID Density Lay) F 2.869 2 F 1.992 2 M .384 2 F 2.676 2 F 4.000 2 M 0.460 24 F 2.845 24 M .385 24 F 2.374 24 M .441 24 M .395 34 M .341 34 F 2.319 34 F 2.405 34 M .399 34

[0116] Thus, the data show that using yeast as a host, male and female eggs can be differentiated based on the level of estrogen receptor transactivation observed in the LifeSensors™ assay. The robustness of the estrogen sensor was tested under different conditions, such as incubation time of eggs, chick species, contamination of blood in the allantoic fluids and the like. All of the experiments demonstrated that the yeast-based estrogen sensor is extremely robust and was successful in determination of the chicken gender 100% of the time.

[0117] The ability of the estrogen sensor was also evaluated to determine the sex of different chicken species. See Table 5. Five allantoic fluid samples from each of three different broiler breeds were tested for analysis. Arbor Acres×Classic Yield (AA×CY), Hubbard×Petersen (H×P), and Cobb×Cobb (C×C) strains were the three different breeds evaluated. The assay clearly distinguished between Day 17 male and female embryos regardless of breed. Optical densities less than 0.650 were considered male and optical densities greater than 0.650 were considered female. TABLE 5 Effect of broiler breed and gender sorting of allantoic fluid by Estrogen Sensor Assay. Sample Optical Sex Breed Density M AA X CY .469 M AA X CY .437 F AA X CY 1.519 F AA X CY 1.430 M AA X CY .492 M H X P .368 M H X P .444 F H X P 2.869 M H X P .389 F H X P 1.642 F C X C 2.187 M C X C .649 F C X C 2.613 M C X C .471 M C X C .458

[0118] Sex Specific Signal Present in the Allantoic Fluid Samples of Turkey can also be Detected by Yeast-Based Estrogen Sensor.

[0119] Ten allantoic fluid samples from Day 22 Nicholas Turkey embryos were analyzed using classical estrogen analysis by radioimmunoassays. The assay-clearly delineated the sex of the turkey embryos. See FIG. 6. Yeast-based estrogen sensor was subsequently used to gender sort. See Table 6. Samples with optical densities less than 0.700 are male and samples with optical densities greater than 0.700 are females. Turkey embryos had a higher average optical density than the chicken samples tested. TABLE 6 Ability to gender sort allantoic fluid from Day 22 Nicholas Turkey embryos. Optical Sex Density M .354 F 2.891 F 2.866 F 4.000 M .419 M .445 M .453 F 4.000 F 4.000 F 4.000

[0120] Yeast-Based Estrogen Sensor can Differentiate Sex at Different Embryonic Stages.

[0121] In order to assess whether the methods of the invention were effective at differentiating sex at different embryonic stages, allantoic fluid samples were obtained from embryos at different stages and assessed for estrogen transactivating activity. See Table 7 TABLE 7 Effect of embryo age on ability to gender sort allantoic fluids. Embryo LS ID SEX ID Age .438 M 13 .566 F 13 .853 F 13 .342 M 13 .305 M 13 .338 M 15 .340 M 15 .376 M 15 .389 M 15 .368 M 15 .531 M 17 .946 F 17 1.270 F 17 .414 M 17 .434 M 17 1.624 F 18 2.292 F 18 2.966 F 18 0.52 M 18 1.285 F 18

[0122] Note—LS ID is LifeSensor sex identification, sex ID is identification of sex by opening the embryo and dissection to manually determine the sex.

EXAMPLE III Production and Secretion of Beta-Galactosidase in Yeast

[0123] In the previous example, exogenous GUS was employed to cleave the estrogen-glucuronide conjugates. This example shows that the active GUS enzyme can be produced in yeast and effectively used to cleave estrogen conjugates present in allantoic fluids. A series of plasmids were constructed as described in Table 8. In the assays shown, plasmid pRS425-GPDp-Ub-GUS that secretes GUS at high concentrations was employed.

[0124] GUS activity inside and outside the cell was measured as follows: Yeast cells were grown in synthetic complete media without leucine to OD₆₀₀=0.5. 50 μL of cell suspension was transferred to 96-well plates. The cell suspension was transferred into eppendorf microfuge tubes and centrifuged at maximal speed on bench top centrifuge for 5 minutes. 50 μL of media (cell-free media) was transferred to 96 microplates wells. 50 μL of PNP-Gluc-2×“Z” Sarcosine-buffer [120 mM Na₂HPO₄, 80 mM NaH₂PO₄, 20 mM KCl, 2 mM MgSO₄, 100 mM beta-mercaptoethanol (Sigma), pH 7.0, 0.4% lauroyl sarcosine (Sigma), 0.5 mg/mL PNP-Gluc (PNP-Gluc is an abbreviation of p-NITROPHENYL-BETA-D-GLUCURONIC ACID;, Diagnostic Chemicals limited)] was added to each well. The buffer was freshly prepared. After incubation at 37° C. for 1 hour . The reaction was stopped by adding 100 μL of quenching solution 0.5 M Na₂CO₃. OD₄₀₅ was measured in a micro plate reader (Biotek) at a wavelength of 405-450 nanometers to estimate the relative enzymatic activity of GUS.

[0125] It has been previously established that attachment of ubiquitin, a 76 amino acid, highly conserved protein to the N-terminus of other proteins enhances the expression of fused proteins several fold. However, it is not known whether ubiquitin plays any role in the extracellular secretion of proteins. Accordingly, as described herein, several GUS yeast expression vectors have been designed wherein the C-terminus of ubiquitin was attached to the N-terminus of GUS (GDPp-UB-GUS). In addition, a factor secretory sequences were attached at the N-terminus of the ubiquitin-GUS fusion (GPD-α-factor-GUS) as well as between ubiquitin and the GUS gene (GDP-UB-α-factor-GUS). The fusion of ubiquitin increases the stability of the recombinant proteins and preserves their biological properties, thus enhancing the quality and quantity of the proteins that are expressed in yeast and E. coli [28, 29]. TABLE 8 GUS Expression in the Cells and Secretion of the Protein. GUS GUS Activity Activity Vector Signal Inside Outside the (pRS425) Promoter Sequence Cells Cells ADH1-GUS1 ADH1 — +++ − ADH1-α-factor- ADH1 α-factor + − GUS1 GPD-α-factor- GPD α-factor ++ − GUS1 GPD-Ub-GUS1 GPD Ubiquitin ++++ ++++ GPD-Ub-α-factor- GPD Ubiquitin-α- ++++ + GUS1 factor GPD-α-factor- GPD α-factor- +/++ + Ub (pro)-GUS1 Ubiquitin(pro) GPD-α-factor- GPD α-factor- + + Ub (met)-GUS1 Ubiquitin(met) CUP1-Ub-GUS1 CUP1 Ubiquitin ++++ ++

[0126] The data described in Table 8 show that attachment of ubiquitin increases expression levels of GUS several fold. The data also shows that only the ubiquitin fusions (with or without α-factor secretory sequences) efficiently secrete GUS. The small amount of GUS activity observed in non-secretory GUS expression strains may be due to release following lysis of dead cells.

EXAMPLE IV Gender Sorting Sensor Development

[0127] The plasmid pRS425-GPDp-Ub-GUS was assessed in additional experiments. This plasmid was used due to its robust GUS expression and high enzymatic activity of GUS in yeast culture media. The GUS producing plasmid was transformed into several yeast strains along with plasmid for expression of human estrogen receptor (YEpE12; See FIG. 4) and estrogen-inducible reporter gene (YRpE2; See FIG. 3A). The strains were screened for growth and GUS production. A yeast strain (BJ 1991) has been identified that grew rapidly with GUS plasmid and produced the highest levels (units) of GUS per mg protein. In addition, this strain was also tolerant of estrogen receptor expression and provides excellent response to estrogen in estrogen transactivation assays.

[0128] Synthetic yeast selective growth media have pH ranges between 4.5 to 5.5. The pH optimum for E. coli GUS was 6.8 as indicated by the Sigma protocol for GUS assay. To maximize growth of yeast and GUS activity, new media conditions were developed that allow optimum growth of yeast as well as robust allantoic estrogen-conjugate responsiveness.

[0129] The yeast strain BJ 1991 was transformed with plasmid pRS425-GPDp-Ub-GUS and grown in the standard yeast media (complete media without leucine, 22). The culture media was supplemented with different salt and buffering conditions by diluting 1:9 with NEB buffer 1, 2, 3, 4 10×-buffers (New England Biolabs). The yeast cells for all the buffering conditions were inoculated at the same OD₆₀₀ 0.1 and grown overnight. No differences were observed in growth rates of the culture. GUS activity was determined after 24 hours of growth in media, as well as in cell lysates using PNP-gluc as a substrate. The GUS activities were measured as described in EXAMPLE III. The data are provided in Table 9. TABLE 9 GUS secretion and activity in cells grown in different media (NEB1-NEB4) GUS activity GUS activity Media in media in cells NEB1 0.117 2.693 NEB2 0.107 2.337 NEB3 0.138 2.963 NEB4 0.945 2.939 Standard 0.87 2.535

[0130] As shown in Table 9, NEB buffer 4 and salt conditions provide the best GUS expression and secretion levels in the media. As demonstrated herein, the final pH of the media is 6.4 after dilution (1:10) of NEB4 (10×) with standard media. Hence, for optimal GUS activity in gender sorting assays, all the experiments and cell growth were carried out in NEB 4 buffer and media conditions. The details of the media are described below.

[0131] Mixing Transactivator and GUS Producing Strains to Monitor Gender

[0132] As shown above for the test media assessed, use of the NEB4 media provided optimized results for extracellular secretion of GUS from yeast. In the next step, NEB4 media was used to grow yeast and for monitoring gender. There were two approaches to monitor gender: a) using two yeast strains—one for GUS production and the other as the estrogen sensor and b) using a single yeast strain that has been transformed to express both GUS and the necessary components of the estrogen sensor. For the first approach, BJ 1991 cells harboring GPD-Ub-GUS1 were grown independently (GUS producer strain) or transformed with only the human estrogen receptor and ERE-beta-Galactosidase reporter vectors (estrogen transactivator strain). Two batches of cells were thereby generated, one producing secretory GUS and the other strain harboring only the transactivator and reporter gene. Cells were grown in liquid modified media following the brief protocol set forth below.

[0133] 1. GUS producer cells were grown in liquid synthetic complete NEB4 media without leucine to OD₆₀₀=1-2

[0134] 2. Transactivator cells were grown in liquid synthetic complete NEB4 media without uracil and tryptophan media overnight to OD₆₀₀=1-2.

[0135] 3. Transactivator cells were diluted 1/10 or 1/20 in NEB4 complete media (pH=6.4) to OD₆₀₀=0.1

[0136] 4. 50 μL of GUS producer from (1), 50 μL of Transactivator in NEB4 from (3) and 8 μL of Male or Female allantoic fluid were added to wells in a microtiter plate.

[0137] 5. Plates were covered with sealer and incubated at 30° C. in a shaker for 4 h.

[0138] 6. 100 μL of 2×“Z”-ONPG buffer was then added.

[0139] 7. Incubate at 37° C. for 10 minutes to 1 h.

[0140] 8. Add 100 μL of quenching solution 0.5M Na₂CO₃.

[0141] 9. Measure at OD₄₀₅

[0142] For the second approach, employing a single yeast strain, the BJ1991 strain was transformed with three plasmids: 1) a GUS enzyme expression vector (pRS425-GPDp-Ub-GUS); 2) an expression vector for human estrogen receptor alpha (YEpE12); and 3) a vector expressing an estrogen inducible reporter (YrpE2). Briefly, the BJ1991 yeast strain was transformed with all three expression vectors and grown in liquid synthetic complete NEB4 media without leucine, uracil and tryptophan to OD₆₀₀=1-2. The cells were diluted 1/10 or 1/20 in NEB4 complete media (final pH=6.4) to OD₆₀₀=0.2. To each well of 96-well plate, 4 μL of Male or Female allantoic fluid were added. 100 μl of the diluted cell suspension was then added. Plates were covered with sealer and incubated at 30° C. at shaker for 4 h. 100 μL of 2×“Z”-ONPG buffer was then added and the samples incubated an additional 10 minutes to 1 hour at 37° C. 100 μL of quenching solution (0.5M Na₂CO₃) was then added and the OD₄₀₅ measured. Both approaches efficiently distinguished male from female embryos.

[0143] Table 10 presents data of gender monitoring using 1 yeast strain harboring all three plasmids. Allantoic fluids OD405 × 1000 Sex DMSO 449 estrogen 1 nM 2982.5 N191 711 Male N219 719.5 Male N212 632 Male N216 696.5 Male N215 661.5 Male N224 836 Male N229 1342 Female N207 1598.5 Female N228 1737 Female N230 1630.5 Female N199 2638.5 Female N200 2812.5 Female N201 2508.5 Female N202 1509 Female N203 2544.5 Female N209 2695 Female N210 1625.5 Female N211 2359.5 Female N214 2894.5 Female N218 1973 Female N220 2950 Female

EXAMPLE V Male/Female Sex Sorting using Superior Substrates for Measuring Enzymatic Activity of Beta-Galactosidase

[0144] Many substrates for measuring beta-galactosidase (beta-Gal) activity are commercially available. Examples include ONPG and PNPG (Diagnostic chemicals, Limited) which are colorimetric substrates for beta-Gal. End products of these compounds have yellow color and are measured at absorption wave length 405 nM. Similar to ONPG, PNPG can be used as a beta-galactosidase substrate to distinguish male verse female eggs. MuGal (Diagnostic chemicals, Limited) is another substrate, whose end product emits yellow fluorescence that can be measured using the appropriate excitation/emission filter. Resorufin-beta-D-galactopyranoside (Sigma) is a red fluorescent substrate for beta-Gal. The advantage of using substrates that emit red fluorescence is that living organism do not emit red autofluorescence. Therefore any autofluorescent background due to cell debris, or blood contamination of the allantoic fluids should be zero.

[0145] One advantage of the present transactivation system is that the assay is relatively inexpensive to perform. To enhance cost-effectiveness, serial dilutions of substrates were tested in the transactivation assays described herein to ascertain the effects of such cost-saving measures and the ability to distinguish males from females. Ten-fold dilution of ONPG and PNPG compromised the male/female ratio readout (data not shown). A ten-fold dilution of the resorufin substrate, however, did not affect the male/female signal ratio. A 5-10 fold difference in readout between male and female samples was maintained despite sample dilution.

[0146] Accordingly, assays were performed using resorufin as substrate at low concentration and allantoic fluids from 30 eggs at 17-Days of incubation. Table 11 shows the results for 24 samples in comparison with sexing data obtained by open egg dissection. Clearly, the method of the present invention provides the accuracy of conventional, time-consuming methods, but in a fraction of the time.

[0147] Table 11 shows sec identification using Lifesensor with resorufin- beta-D-galactopyranoside as a substrate in comparison with sex identification using open dissection of embryos. Egg number 582 583 584 585 586 587 588 589 Sex ID Female Male Male Female Male Female Male Male Readout 0.1358 0.0000 0.0000 0.0865 0.0000 0.1106 0.0000 0.0035 Egg number 590 591 592 593 594 595 596 597 Sex ID Female Male Female Female Female Female Male Female Readout 0.1057 0.0032 0.1143 0.1240 0.1229 0.1059 0.0000 0.1236 Egg number 598 599 600 601 602 603 604 605 Sex ID Male Female Female Male Male Male Male Female Readout 0.0019 0.1096 0.1126 0.0120 0.0270 0.0000 0.0000 0.1060

[0148] The results depicted in Table 11 are graphed in FIG. 7. There is 100% match between sex and red fluorescent readout: the females have a high readout (higher than 0.0600), and the males have a low readout (lower than 0.01) reflecting differences in estrogen level. Thus, using resorufin-beta-D-galactopyranoside as beta-galactosidase substrate, the background signal has been diminished, thereby generating a higher signal to noise ratio.

EXAMPLE VI Modification of Gender Sorting Sensor to Shorten Assay Time and Increase Robustness

[0149] The present inventors have modified the gender sorting assay system to include the use of heat shock promoters. Yeast heat shock promoters such as HSP104, HSP26 and SSA4 are robust promoters which are activated rapidly in response heat shock stress (see Tijirina and Sayer 1998). High levels of these heat shock proteins have been observed within fifteen minutes of exposure of yeast cells to either high temperature (38° C.) or osmotic pressure. Transcriptional activation of HSP26, HSP104 and SSA4 increased 55-, 39-, and 167-fold, respectively, after 15 minutes of exposure to heat shock conditions (Tijirina and Sayre, 1998). Accordingly, an SSA4-based estrogen inducible reporter has been constructed that responds to activation signals with faster kinetics (at least twice as fast) than the CYC1-based reporter described above.

[0150] The SSA4-based estrogen inducible reporter plasmid YRpE2SSA4-lacZ was constructed using the ecdysone inducible reporter plasmid PBRSS 6×EcRE-lacZ as the backbone construct (Tran et al., 2001). The Sal1-BamH1 fragment comprising the 6×EcRE ecdysone response elements along with CYC1 promoter of PBRSS 6×EcRE-lacZ have been replaced with a Sal1-BamH1 fragment that contains 2×EREs plus part of the SSA4 promoter. The Sal1-BamH1 DNA fragment comprising 2×EREs plus part of the SSA4 promoter was generated by PCR amplification of yeast Saccharomyces cerevisiae genomic DNA using two primers: SSA4-forward primer containing two ERE elements: 5-GCGTCGACTCTGGTCACAGTGACCggtcacagtgaccTTATGGAAGCACCAAG-3′ (SEQ ID NO: 5; the Sal1 site is underlined and the two estrogen response elements are indicated in italics) and SSA4-reverse primer starting from the ATG codon: 5′-GTGGATCCCATGATTATTGTTTTG-3′ (SEQ ID NO: 6; the BamH 1 site is underlined). Of note, SSA4 is a heat shock inducible gene, the transcription of which is rapidly and robustly induced upon heat shock exposure (Tijirina and Sayre, 1998). A PCR product generated using the-above template and primers would, therefore, comprise the SSA4 heat shock promoter operably linked to two EREs and flanked by Sal1 and BamH1 restriction enzyme sites.

[0151] The data presented in the Table 12 demonstrated that the response of the SSA4-based estrogen inducible reporter plasmid YRpE2SSA4-lacZ to estrogen activation was at least twice as fast as that of the CYC1 promoter-based reporter. The development of the SSA4-ERE reporter system, therefore, significantly expedited the gender sorting ability of the yeast sensor assay. See Tables 13 and 14.

[0152] The following is a brief protocol of the estrogen transactivation assays used to compare the CYC1 promoter-based reporter to the SSA4 promoter-based reporter.

[0153] 1. BJ1991 yeast cells containing YEpE12 (estrogen expressing vector), pRS425-GPDp-Ub-GUS and either reporter plasmid YRpE2 or YRpE2SSA4-lacZ were grown in liquid synthetic MP medium to OD₆₀₀=1-2.

[0154] 2. Yeast culture was diluted in liquid MP media to OD₆₀₀=0.2.

[0155] 3. 100 μL of yeast cell suspension were spiked into each well of a 96-well microtiter plate. Estrogen (diluted in DMSO) was added to the wells to a final concentration 5 nM.

[0156] 4. Plates were covered with sealer and incubated at 30° C.

[0157] 5. At intervals of 15 minutes, 100 μL of 2×“Z”-ONPG buffer (without beta-mercaptoethanol) was added.

[0158] 6. Incubations were performed at 30° C. for 15 minutes.

[0159] 7. Optical densities were determined at OD₄₀₅. TABLE 12 Time/response comparison of two estrogen inducible reporters (CYC1 promoter-based and SSA4 promoter-based) in response to 5 nM estrogen. The data shown is the average of three independent measurements. Time of CYC1- SSA4- incubation reporter reporter  0 minutes 0.144 0.157  15 minutes 0.133 0.167  30 minutes 0.228 0.241  45 minutes 0.185 0.535  60 minutes 0.206 0.720  75 minutes 0.250 0.805  90 minutes 0.378 0.857 105 minutes 0.268 1.041 120 minutes 0.338 0.991

[0160] As shown in FIG. 8 and Table 12, the SSA4-based reporter responded to estrogen in only 30-45 minutes, whereas the SSA4-based sensor required approximately 1.5 to 2 hours of incubation time to distinguish male and female allantoic fluids. These results suggest that the cleavage of estradiol glucuronide conjugates to free estradiol is a time limiting factor in such assays. The amount of GUS secreted by yeast cell suspensions (OD₆₀₀=0.2) into the growth media after four hours of growth was less than 0.01 GUS activity units, as compared to a standard titration series of purified E. coli GUS (Sigma) using PNPG as a substrate. The present inventors have discovered that supplemention of 100 μl cell suspension reactions with 0.1-1 activity units of GUS (Sigma) reduces the assay time from 2 hours to less than 1 hour.

[0161] The following protocol was performed to titrate the GUS activity in allantoic fluid assays.

[0162] 1. BJ1991 yeast cells comprising YEpE12 (estrogen expressing vector), pRS425-GPDp-Ub-GUS and reporter plasmid YRpE2 or YRpE2SSA4-lacZ were grown in liquid synthetic MP medium to OD₆₀₀=1-2.

[0163] 2. Yeast cell cultures were diluted in liquid MP media to OD₆₀₀=0.2.

[0164] 3. E. coli GUS (Sigma #G-7396) was added to yeast suspensions to achieve different final concentrations of 100, 10, 1, 0.1, 0.01, 0.001, 0.0001 enzymatic activity units per 100 μl of yeast suspension.

[0165] 4. Eighty microliters of yeast cell suspension (containing exogenous GUS) were spiked into individual wells of a 96-well microtiter plate. In each well there was either 20 μl of male or female allantoic fluids.

[0166] 5. Plates were covered with sealer and incubated for 1 hour at 30° C.

[0167] 6. One hundred microliters of 2×“Z”-ONPG buffer (without beta-mercaptoethanol) was then added.

[0168] 7. Incubation was performed at 30° C. for 15 minutes.

[0169] 8. The number of pixels in each well was measured using a CCD camera. TABLE 13 GUS enzyme titration and the ability of the SSA-4 based sensor to distinguish between male and female allantoic fluids as measured using a CCD camera. The GUS titration was performed as described above. GUS CYC1 CYC1 SSA4 SSA4 SSA4 SSA4 (units) Male Female Male Female Male Female 100 0 20 7 400 7 420 10 0 7 0 500 0 400 1 0 7 0 620 0 450 0.1 0 2 0 560 0 400 0.01 0 0 0 320 0 50 0.001 2 0 0 40 0 5 0.0001 1 0 2 5 5 30 0 1 2 10 10 10 40

[0170] The data presented in the Table 13 demonstrated that 0.1-1 units of GUS were sufficient to enhance the sensitivity of gender sorting assays. The cost of 25,000 units of E. coli GUS (Sigma) is $16, which means that the additional cost associated with the above-modified assays was less than 0.0075 cents (0.1 unit) of exogenous GUS per assay well to effect a 50% reduction in assay time (reduced from 2 to 1 hour).

[0171] The results shown in Table 14 demonstrate the ability of the modified gender sorting assay to accurately distinguish male and female allantoic fluid samples. As shown, five male and five female allantoic fluid samples were tested in the modified gender sorting assay. The assay was performed with the indicated allantoic fluids, using the SSA4-reporter construct in the presence of exogenous GUS (0.1 units per assay) for one hour of incubation time, which was followed by a substrate reaction of 15 minutes. TABLE 14 Ability of the SSA-4 based sensor in combination with 0.1 unit of exogenous GUS to distinguish between male and female allantoic fluids using either a colorimetric microplate reader or CCD camera. SSA4, clone1 SSA4, clone 2 OD405 CCD OD405 CCD Allantoic measurement measurement measurement measurement Male 0.200 5 0.250 6 Male 0.209 7 0.221 0 Male 0.254 7 0.284 9 Male 0.329 6 0.337 6 Male 0.232 9 0.257 20 Female 0.672 520 0.68 600 Female 0.607 600 0.615 675 Female 0.506 600 0.487 700 Female 0.514 590 0.506 640 Female 0.561 600 0.574 650

EXAMPLE VII Detection of Steroid and Drug-Conjugates in Biological Fluids

[0172] The human body actively glucuronidates a variety of steroids and xenobiotics. The liver contains several UDP-glucuronsyltranferases (UGT) that glucuronidate many drugs and steroids (Burchell et al, 1994). Glucuronidation of steroids and drugs is a widely used mechanism for the inactivation and removal of these agents from the body. Drug and steroid-glucuronides or sulfates have lower affinity for their cognate receptors or targets. If one can de-conjugate a particular drug or xenobiotic, a receptor or drug-target driven sensor can then be used to estimate the amount of the steroid or drug released from the conjugate. The glucuronidases have rather broad specificity for glucuronidated molecules. Hence, it is possible to use a selected series of the glucoronidase expression vectors that are transformed into a yeast strain harboring the target receptor or enzyme. Incubation of biological fluids, including without limitation, sera, urine or saliva will convert low affinity inactive drug steroid-conjugate into a high affinity active drug that will bind to the target receptor to activate the receptor and promote the transactivation signal.

[0173] An exemplary drug detection assay can be performed using the following steps:

[0174] 1) The appropriate GUS producing cells are transformed with the target receptor expression vector and the reporter gene.

[0175] 2) The GUS secretory cells are grown in selective media achieving an O.D=0.2 or alternatively, an O.D that allows maximal cleavage of the drug conjugate. The cells, 20-100 μL are transferred to 96 or 384 well plates.

[0176] 3) To each well 1-10 μl of a biological ample is added. The salt and buffer conditions are optimized in cell suspension to maximize GUS enzyme function. The suspension is approximately 5-30 microliters. Different volumes of biological fluids are assayed in duplicate.

[0177] 4) To each well, appropriate substrate is added to determine the induction of the reporter gene as described above for Examples III, IV and V.

[0178] 5) The amount of the de-conjugated target receptor ligand is estimated by comparing the signal obtained from the biological fluid to a standardized control ligand assayed at the same time.

[0179] 6) Standard control reactions, e.g., with ligands that target the receptor under investigation, are performed on the same plate in which the conjugated ligand or xenobiotics are assayed. Appropriate software is then utilized to facilitate calculation of the concentration of the conjugated xenobiotics following the computation of the signal detected from the control wells.

[0180] Detection of conjugated xenobiotics by the receptor-based sensors of the invention has several applications in determining the sensitivity and toxicity of various drugs, ligands and steroids in the human population.

[0181] For example, several drugs become more toxic once they are glucuronidated or modified by drug metabolism pathway such as the cytochrome P450 series of enzymes. A rapid sensor that efficiently assesses the level of glucuronidated drugs will aid the clinician in the development of drug tolerance studies as well as toxic dose determinations in selected patients.

[0182] Conversely, conjugation of xenobiotics is often attributed to the loss of activity and clearance from the human system. This is due to the ability of different individuals to glucuronidate certain steroid and other xenobiotics and specifically the function of human UDP-glucuronsyltranferases. It is also feasible that the glucuronidation pattern of an individual is related to drug sensitivity and toxicity. In this respect the receptor and GUS encapsulated sensors are tools for studying pharmocogenomics of populations. Thus the sensors can be used as tools to stratify populations for clinical trials.

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[0224] While certain preferred embodiments of the present invention have been described and specifically exemplified above, it is not intended that the invention be limited to such embodiments. Various modifications may be made to the invention without departing from the scope and spirit thereof as set forth in the following claims.

1 10 1 25 DNA Artificial Sequence primer 1 gctcgagagc acagatgctt cgttg 25 2 25 DNA Artificial Sequence primer 2 gcaaagcttg gagttgattg tatgc 25 3 32 DNA Artificial Sequence primer 3 accaagctta ttcgaaggat ccaaacgatg ag 32 4 31 DNA Artificial Sequence primer 4 gccaagcttg gagcctctct tttctcgaga g 31 5 53 DNA Artificial Sequence primer 5 gcgtcgactc tggtcacagt gaccggtcac agtgacctta tggaagcacc aag 53 6 24 DNA Artificial Sequence primer 6 gtggatccca tgattattgt tttg 24 7 9877 DNA Artificial Sequence CyC1 based estrogen inducible reporter YRpE2 7 gaattctgaa ccagtcctaa aacgagtaaa taggaccggc aattcttcaa gcaataaaca 60 ggaataccaa ttattaaaag ataacttagt cagatcgtac aataaagctt tgaagaaaaa 120 tgcgccttat tcaatctttg ctataaaaaa tggcccaaaa tctcacattg gaagacattt 180 gatgacctca tttctttcaa tgaagggcct aacggagttg actaatgttg tgggaaattg 240 gagcgataag cgtgcttctg ccgtggccag gacaacgtat actcatcaga taacagcaat 300 acctgatcac tacttcgcac tagtttctcg gtactatgca tatgatccaa tatcaaagga 360 aatgatagca ttgaaggatg agactaatcc aattgaggag tggcagcata tagaacagct 420 aaagggtagt gctgaaggaa gcatacgata ccccgcatgg aatgggataa tatcacagga 480 ggtactagac tacctttcat cctacataaa tagacgcata taagtacgca tttaagcata 540 aacacgcact atgccgttct tctcatgtat atatatatac aggcaacacg cagatatagg 600 tgcgacgtga acagtgagct gtatgtgcgc agctcgcgtt gcattttcgg aagcgctcgt 660 tttcggaaac gctttgaagt tcctattccg aagttcctat tctctagaaa gtataggaac 720 ttcagagcgc ttttgaaaac caaaagcgct ctgaagacgc actttcaaaa aaccaaaaac 780 gcaccggact gtaacgagct actaaaatat tgcgaatacc gcttccacaa acattgctca 840 aaagtatctc tttgctatat atctctgtgc tatatcccta tataacctac ccatccacct 900 ttcgctcctt gaacttgcat ctaaactcga cctctacatc ttttatgttt atctctagta 960 ttactcttta gacaaaaaaa ttgtagtaag aactattcat agagtgaatc gaaaacaata 1020 cgaaaatgta aacatttcct atacgtagta tatagagaca aaatagaaga aaccgttcat 1080 aattttctga ccaatgaaga atcatcaacg ctatcacttt ctgttcacaa agtatgcgca 1140 atccacatcg gtatagaata taatcgggga tgcctttatc ttgaaaaaat gcacccgcag 1200 cttcgctagt aatcagtaaa cgcgggaagt ggagtcaggc tttttttatg gaagagaaaa 1260 tagacaccaa agtagccttc ttctaacctt aacggaccta cagtgcaaaa agttatcaag 1320 agactgcatt atagagcgca caaaggagaa aaaaagtaat ctaagatgct ttgttagaaa 1380 aatagcgctc tcgggatgca tttttgtaga acaaaaaaga agtatagatt ctttgttggt 1440 aaaatagcgc tctcgcgttg catttctgtt ctgtaaaaat gcagctcaga ttctttgttt 1500 gaaaaattag cgctctcgcg ttgcattttt gttttacaaa aatgaagcac agattcttcg 1560 ttggtaaaat agcgctttcg cgttgcattt ctgttctgta aaaatgcagc tcagattctt 1620 tgtttgaaaa attagcgctc tcgcgttgca tttttgttct acaaaatgaa gcacagatgc 1680 ttcgttaaca aagatatgct attgaagtgc aagatggaaa cgcagaaaat gaaccgggga 1740 tgcgacgtgc aagattacct atgcaataga tgcaatagtt tctccaggaa ccgaaataca 1800 tacattgtct tccgtaaagc gctagactat atattattat acaggttcaa atatactatc 1860 tgtttcaggg aaaactccca ggttcggatg ttcaaaattc aatgatgggt aacaagtacg 1920 atcgtaaatc tgtaaaacag tttgtcggat attaggctgt atctcctcaa agcgtattcg 1980 aatatcattg agaagctgca gcgtcacatc ggataataat gatggcagcc attgtagaag 2040 tgccttttgc atttctagtc tctttctcgg tctagctagt tttactacat cgcgaagata 2100 gaatcttaga tcacactgcc tttgctgagc tggatcaata gagtaacaaa agagtggtaa 2160 ggcctcgtta aaggacaagg acctgagcgg aagtgtatcg tacagtagac ggagtatact 2220 agtatagtct atagtccgtg gaattctcat gtttgacagc ttatcatcga taagcttgct 2280 tttcaattca tctttttttt ttttgttctt ttttttgatt ccggtttctt tgaaattttt 2340 ttgattcggt aatctccgag cagaaggaag aacgaaggaa ggagcacaga cttagattgg 2400 tatatatacg catatgtggt gttgaagaaa catgaaattg cccagtattc ttaacccaac 2460 tgcacagaac aaaaacctgc aggaaacgaa gataaatcat gtcgaaagct acatataagg 2520 aacgtgctgc tactcatcct agtcctgttg ctgccaagct atttaatatc atgcacgaaa 2580 agcaaacaaa cttgtgtgct tcattggatg ttcgtaccac caaggaatta ctggagttag 2640 ttgaagcatt aggtcccaaa atttgtttac taaaaacaca tgtggatatc ttgactgatt 2700 tttccatgga gggcacagtt aagccgctaa aggcattatc cgccaagtac aattttttac 2760 tcttcgaaga cagaaaattt gctgacattg gtaatacagt caaattgcag tactctgcgg 2820 gtgtatacag aatagcagaa tgggcagaca ttacgaatgc acacggtgtg gtgggcccag 2880 gtattgttag cggtttgaag caggcggcgg aagaagtaac aaaggaacct agaggccttt 2940 tgatgttagc agaattgtca tgcaagggct ccctagctac tggagaatat actaagggta 3000 ctgttgacat tgcgaagagc gacaaagatt ttgttatcgg ctttattgct caaagagaca 3060 tgggtggaag agatgaaggt tacgattggt tgattatgac acccggtgtg ggtttagatg 3120 acaagggaga cgcattgggt caacagtata gaaccgtgga tgatgtggtc tctacaggat 3180 ctgacattat tattgttgga agaggactat ttgcaaaggg aagggatgct aaggtagagg 3240 gtgaacgtta cagaaaagca ggctgggaag catatttgag aagatgcggc cagcaaaact 3300 aaaaaactgt attataagta aatgcatgta tactaaactc acaaattaga gcttcaattt 3360 aattatatca gttattaccc gatcaaaaat catcgcttcg ctgattaatt accccagaaa 3420 taaggctaaa aaactaatcg cattatcatc ctatggttgt taatttgatt cgttcatttg 3480 aaggtttgtg gggccaggtt actgccaatt tttcctcttc ataaccataa aagctagtat 3540 tgtagaatct ttattgttcg gagcagtgcg gcgcgaggca catctgcgtt tcaggaacgc 3600 gaccggtgaa gacgaggacg cacggaggag agtcttcctt cggagggctg tcacccgctc 3660 ggcggcttct aatccgtact tcaatatagc aatgagcagt taagcgtatt actgaaagtt 3720 ccaaagagaa ggttttttta ggctaatcga cgtcgacaat cttacatggt ctacctttga 3780 tgacaacgaa accattcttt ctcaaggcag aacattgcat tgggtaggtg gcggaggcac 3840 cagcgtcagc attttcaaag gtgtgttctt cgtcagacat gttttagtgt gtgaatgaaa 3900 taggtgtatg ttttcttttt gctagacaat aattaggaac aaggtaaggg aactaaagtg 3960 tagaataaga ttaaaaaaga agaacaagtt gaaaaggcaa gttgaaattt caagaaaaaa 4020 gtcaattgaa gtacagtaaa ttgacctgaa tatatctgag ttccgacaac aatgagttta 4080 ccaaagagaa caatggaata ggaaactttg aacgaagaaa ggaaagcagg aaaggaaaaa 4140 atttttaggc tcgaggtcca aagtcaggtc acagtgacct gatcaaagtt ctcgaggtcc 4200 aaagtcaggt cacagtgacc tgatcaaagt tctcgagcag atccgccagg cgtgtatata 4260 gcgtggatgg ccaggcaact ttagtgctga cacatacagg catatatata tgtgtgcgac 4320 gacacatgat catatggcat gcatgtgctc tgtatgtata taaaactctt gttttcttct 4380 tttctctaaa tattctttcc ttatacatta ggtcctttgt agcataaatt actatacttc 4440 tatagacacg caaacacaaa tacacacact aaattaataa tgaccggatc cggagcttgg 4500 ctgttgcccg tctcactggt gaaaagaaaa accaccctgg cgcccaatac gcaaaccgcc 4560 tctccccgcg cgttggccga ttcattaatg cagctggcac gacaggtttc ccgacttaat 4620 cgccttgcag cacatccccc tttcgccagc tggcgtaata gcgaagaggc ccgcaccgat 4680 cgcccttccc aacagttgcg cagcctgaat ggcgaatggc gctttgcctg gtttccggca 4740 ccagaagcgg tgccggaaag ctggctggag tgcgatcttc ctgaggccga tactgtcgtc 4800 gtcccctcaa actggcagat gcacggttac gatgcgccca tctacaccaa cgtaacctat 4860 cccattacgg tcaatccgcc gtttgttccc acggagaatc cgacgggttg ttactcgctc 4920 acatttaatg ttgatgaaag ctggctacag gaaggccaga cgcgaattat ttttgatggc 4980 gttaactcgg cgtttcatct gtggtgcaac gggcgctggg tcggttacgg ccaggacagt 5040 cgtttgccgt ctgaatttga cctgagcgca tttttacgcg ccggagaaaa ccgcctcgcg 5100 gtgatggtgc tgcgttggag tgacggcagt tatctggaag atcaggatat gtggcggatg 5160 agcggcattt tccgtgacgt ctcgttgctg cataaaccga ctacacaaat cagcgatttc 5220 catgttgcca ctcgctttaa tgatgatttc agccgcgctg tactggaggc tgaagttcag 5280 atgtgcggcg agttgcgtga ctacctacgg gtaacagttt ctttatggca gggtgaaacg 5340 caggtcgcca gcggcaccgc gcctttcggc ggtgaaatta tcgatgagcg tggtggttat 5400 gccgatcgcg tcacactacg tctgaacgtc gaaaacccga aactgtggag cgccgaaatc 5460 ccgaatctct atcgtgcggt ggttgaactg cacaccgccg acggcacgct gattgaagca 5520 gaagcctgcg atgtcggttt ccgcgaggtg cggattgaaa atggtctgct gctgctgaac 5580 ggcaagccgt tgctgattcg aggcgttaac cgtcacgagc atcatcctct gcatggtcag 5640 gtcatggatg agcagacgat ggtgcaggat atcctgctga tgaagcagaa caactttaac 5700 gccgtgcgct gttcgcatta tccgaaccat ccgctgtggt acacgctgtg cgaccgctac 5760 ggcctgtatg tggtggatga agccaatatt gaaacccacg gcatggtgcc aatgaatcgt 5820 ctgaccgatg atccgcgctg gctaccggcg atgagcgaac gcgtaacgcg aatggtgcag 5880 cgcgatcgta atcacccgag tgtgatcatc tggtcgctgg ggaatgaatc aggccacggc 5940 gctaatcacg acgcgctgta tcgctggatc aaatctgtcg atccttcccg cccggtgcag 6000 tatgaaggcg gcggagccga caccacggcc accgatatta tttgcccgat gtacgcgcgc 6060 gtggatgaag accagccctt cccggctgtg ccgaaatggt ccatcaaaaa atggctttcg 6120 ctacctggag agacgcgccc gctgatcctt tgcgaatacg cccacgcgat gggtaacagt 6180 cttggcggtt tcgctaaata ctggcaggcg tttcgtcagt atccccgttt acagggcggc 6240 ttcgtctggg actgggtgga tcagtcgctg attaaatatg atgaaaacgg caacccgtgg 6300 tcggcttacg gcggtgattt tggcgatacg ccgaacgatc gccagttctg tatgaacggt 6360 ctggtctttg ccgaccgcac gccgcatcca gcgctgacgg aagcaaaaca ccagcagcag 6420 tttttccagt tccgtttatc cgggcaaacc atcgaagtga ccagcgaata cctgttccgt 6480 catagcgata acgagctcct gcactggatg gtggcgctgg atggtaagcc gctggcaagc 6540 ggtgaagtgc ctctggatgt cgctccacaa ggtaaacagt tgattgaact gcctgaacta 6600 ccgcagccgg agagcgccgg gcaactctgg ctcacagtac gcgtagtgca accgaacgcg 6660 accgcatggt cagaagccgg gcacatcagc gcctggcagc agtggcgtct ggcggaaaac 6720 ctcagtgtga cgctccccgc cgcgtcccac gccatcccgc atctgaccac cagcgaaatg 6780 gatttttgca tcgagctggg taataagcgt tggcaattta accgccagtc aggctttctt 6840 tcacagatgt ggattggcga taaaaaacaa ctgctgacgc cgctgcgcga tcagttcacc 6900 cgtgcaccgc tggataacga cattggcgta agtgaagcga cccgcattga ccctaacgcc 6960 tgggtcgaac gctggaaggc ggcgggccat taccaggccg aagcagcgtt gttgcagtgc 7020 acggcagata cacttgctga tgcggtgctg attacgaccg ctcacgcgtg gcagcatcag 7080 gggaaaacct tatttatcag ccggaaaacc taccggattg atggtagtgg tcaaatggcg 7140 attaccgttg atgttgaagt ggcgagcgat acaccgcatc cggcgcggat tggcctgaac 7200 tgccagctgg cgcaggtagc agagcgggta aactggctcg gattagggcc gcaagaaaac 7260 tatcccgacc gccttactgc cgcctgtttt gaccgctggg atctgccatt gtcagacatg 7320 tataccccgt acgtcttccc gagcgaaaac ggtctgcgct gcgggacgcg cgaattgaat 7380 tatggcccac accagtggcg cggcgacttc cagttcaaca tcagccgcta cagtcaacag 7440 caactgatgg aaaccagcca tcgccatctg ctgcacgcgg aagaaggcac atggctgaat 7500 atcgacggtt tccatatggg gattggtggc gacgactcct ggagcccgtc agtatcggcg 7560 gaattccagc tgagcgccgg tcgcgctgcc tcgcgcgttt cggtgatgac ggtgaaaacc 7620 tctgacacat gcagctcccg gagacggtca cagcttgtct gtaagcggat gccgggagca 7680 gacaagcccg tcagggcgcg tcagcgggtg ttggcgggtg tcggggcgca gccatgaccc 7740 agtcacgtag cgatagcgga gtgtatactg gcttaactat gcggcatcag agcagattgt 7800 actgagagtg caccatatgc ggtgtgaaat accgcacaga tgcgtaagga gaaaataccg 7860 catcaggcgc tcttccgctt cctcgctcac tgactcgctg cgctcggtcg ttcggctgcg 7920 gcgagcggta tcagctcact caaaggcggt aatacggtta tccacagaat caggggataa 7980 cgcaggaaag aacatgtgag caaaaggcca gcaaaaggcc aggaaccgta aaaaggccgc 8040 gttgctggcg tttttccata ggctccgccc ccctgacgag catcacaaaa atcgacgctc 8100 aagtcagagg tggcgaaacc cgacaggact ataaagatac caggcgtttc cccctggaag 8160 ctccctcgtg cgctctcctg ttccgaccct gccgcttacc ggatacctgt ccgcctttct 8220 cccttcggga agcgtggcgc tttctcatag ctcacgctgt aggtatctca gttcggtgta 8280 ggtcgttcgc tccaagctgg gctgtgtgca cgaacccccc gttcagcccg accgctgcgc 8340 cttatccggt aactatcgtc ttgagtccaa cccggtaaga cacgacttat cgccactggc 8400 agcagccact ggtaacagga ttagcagagc gaggtatgta ggcggtgcta cagagttctt 8460 gaagtggtgg cctaactacg gctacactag aaggacagta tttggtatct gcgctctgct 8520 gaagccagtt accttcggaa aaagagttgg tagctcttga tccggcaaac aaaccaccgc 8580 tggtagcggt ggtttttttg tttgcaagca gcagattacg cgcagaaaaa aaggatctca 8640 agaagatcct ttgatctttt ctacggggtc tgacgctcag tggaacgaaa actcacgtta 8700 agggattttg gtcatgagat tatcaaaaag gatcttcacc tagatccttt taaattaaaa 8760 atgaagtttt aaatcaatct aaagtatata tgagtaaact tggtctgaca gttaccaatg 8820 cttaatcagt gaggcaccta tctcagcgat ctgtctattt cgttcatcca tagttgcctg 8880 actccccgtc gtgtagataa ctacgatacg ggagggctta ccatctggcc ccagtgctgc 8940 aatgataccg cgagacccac gctcaccggc tccagattta tcagcaataa accagccagc 9000 cggaagggcc gagcgcagaa gtggtcctgc aactttatcc gcctccatcc agtctattaa 9060 ttgttgccgg gaagctagag taagtagttc gccagttaat agtttgcgca acgttgttgc 9120 cattgctgca ggcatcgtgg tgtcacgctc gtcgtttggt atggcttcat tcagctccgg 9180 ttcccaacga tcaaggcgag ttacatgatc ccccatgttg tgcaaaaaag cggttagctc 9240 cttcggtcct ccgatcgttg tcagaagtaa gttggccgca gtgttatcac tcatggttat 9300 ggcagcactg cataattctc ttactgtcat gccatccgta agatgctttt ctgtgactgg 9360 tgagtactca accaagtcat tctgagaata gtgtatgcgg cgaccgagtt gctcttgccc 9420 ggcgtcaaca cgggataata ccgcgccaca tagcagaact ttaaaagtgc tcatcattgg 9480 aaaacgttct tcggggcgaa aactctcaag gatcttaccg ctgttgagat ccagttcgat 9540 gtaacccact cgtgcaccca actgatcttc agcatctttt actttcacca gcgtttctgg 9600 gtgagcaaaa acaggaaggc aaaatgccgc aaaaaaggga ataagggcga cacggaaatg 9660 ttgaatactc atactcttcc tttttcaata ttattgaagc atttatcagg gttattgtct 9720 catgagcgga tacatatttg aatgtattta gaaaaataaa caaatagggg ttccgcgcac 9780 atttccccga aaagtgccac ctgacgtcta agaaaccatt attatcatga cattaaccta 9840 taaaaatagg cgtatcacga ggccctttcg tcttcaa 9877 8 9098 DNA Artificial Sequence SSA4-based estrogen inducible reporter YRpE2SSA4-lacZ 8 gaattctgaa ccagtcctaa aacgagtaaa taggaccggc aattcttcaa gcaataaaca 60 ggaataccaa ttattaaaag ataacttagt cagatcgtac aataaagctt tgaagaaaaa 120 tgcgccttat tcaatctttg ctataaaaaa tggcccaaaa tctcacattg gaagacattt 180 gatgacctca tttctttcaa tgaagggcct aacggagttg actaatgttg tgggaaattg 240 gagcgataag cgtgcttctg ccgtggccag gacaacgtat actcatcaga taacagcaat 300 acctgatcac tacttcgcac tagtttctcg gtactatgca tatgatccaa tatcaaagga 360 aatgatagca ttgaaggatg agactaatcc aattgaggag tggcagcata tagaacagct 420 aaagggtagt gctgaaggaa gcatacgata ccccgcatgg aatgggataa tatcacagga 480 ggtactagac tacctttcat cctacataaa tagacgcata taagtacgca tttaagcata 540 aacacgcact atgccgttct tctcatgtat atatatatac aggcaacacg cagatatagg 600 tgcgacgtga acagtgagct gtatgtgcgc agctcgcgtt gcattttcgg aagcgctcgt 660 tttcggaaac gctttgaagt tcctattccg aagttcctat tctctagaaa gtataggaac 720 ttcagagcgc ttttgaaaac caaaagcgct ctgaagacgc actttcaaaa aaccaaaaac 780 gcaccggact gtaacgagct actaaaatat tgcgaatacc gcttccacaa acattgctca 840 aaagtatctc tttgctatat atctctgtgc tatatcccta tataacctac ccatccacct 900 ttcgctcctt gaacttgcat ctaaactcga cctctacatt ttttatgttt atctctagta 960 ttactcttta gacaaaaaaa ttgtagtaag aactattcat agagtgaatc gaaaacaata 1020 cgaaaatgta aacatttcct atacgtagta tatagagaca aaatagaaga aaccgttcat 1080 aattttctga ccaatgaaga atcatcaacg ctatcacttt ctgttcacaa agtatgcgca 1140 atccacatcg gtatagaata taatcgggga tgcctttatc ttgaaaaaat gcacccgcag 1200 cttcgctagt aatcagtaaa cgcgggaagt ggagtcaggc tttttttatg gaagagaaaa 1260 tagacaccaa agtagccttc ttctaacctt aacggaccta cagtgcaaaa agttatcaag 1320 agactgcatt atagagcgca caaaggagaa aaaaagtaat ctaagatgct ttgttagaaa 1380 aatagcgctc tcgggatgca tttttgtaga acaaaaaaga agtatagatt ctttgttggt 1440 aaaatagcgc tctcgcgttg catttctgtt ctgtaaaaat gcagctcaga ttctttgttt 1500 gaaaaattag cgctctcgcg ttgcattttt gttttacaaa aatgaagcac agattcttcg 1560 ttggtaaaat agcgctttcg cgttgcattt ctgttctgta aaaatgcagc tcagattctt 1620 tgtttgaaaa attagcgctc tcgcgttgca tttttgttct acaaaatgaa gcacagatgc 1680 ttcgttaaca aagatatgct attgaagtgc aagatggaaa cgcagaaaat gaaccgggga 1740 tgcgacgtgc aagattacct atgcaataga tgcaatagtt tctccaggaa ccgaaataca 1800 tacattgtct tccgtaaagc gctagactat atattattat acaggttcaa atatactatc 1860 tgtttcaggg aaaactccca ggttcggatg ttcaaaattc aatgatgggt aacaagtacg 1920 atcgtaaatc tgtaaaacag tttgtcggat attaggctgt atctcctcaa agcgtattcg 1980 aatatcattg agaagctgca gcgtcacatc ggataataat gatggcagcc attgtagaag 2040 tgccttttgc atttctagtc tctttctcgg tctagctagt tttactacat cgcgaagata 2100 gaatcttaga tcacactgcc tttgctgagc tggatcaata gagtaacaaa agagtggtaa 2160 ggcctcgtta aaggacaagg acctgagcgg aagtgtatcg tacagtagac ggagtatact 2220 agtatagtct atagtccgtg gaattctcat gtttgacagc ttatcatcga taagcttttc 2280 aattcaattc atcatttttt ttttattctt ttttttgatt tcggtttctt tgaaattttt 2340 ttgattcggt aatctccgaa cagaaggaag aacgaaggaa ggagcacaga cttagattgg 2400 tatatatacg catatgtagt gttgaagaaa catgaaattg cccagtattc ttaacccaac 2460 tgcacagaac aaaaacctgc aggaaacgaa gataaatcat gtcgaaagct acatataagg 2520 aacgtgctgc tactcatcct agtcctgttg ctgccaagct atttaatatc atgcacgaaa 2580 agcaaacaaa cttgtgtgct tcattggatg ttcgtaccac caaggaatta ctggagttag 2640 ttgaagcatt aggtcccaaa atttgtttac taaaaacaca tgtggatatc ttgactgatt 2700 tttccatgga gggcacagtt aagccgctaa aggcattatc cgccaagtac aattttttac 2760 tcttcgaaga cagaaaattt gctgacattg gtaatacagt caaattgcag tactctgcgg 2820 gtgtatacag aatagcagaa tgggcagaca ttacgaatgc acacggtgtg gtgggcccag 2880 gtattgttag cggtttgaag caggcggcag aagaagtaac aaaggaacct agaggccttt 2940 tgatgttagc agaattgtca tgcaagggct ccctatctac tggagaatat actaagggta 3000 ctgttgacat tgcgaagagc gacaaagatt ttgttatcgg ctttattgct caaagagaca 3060 tgggtggaag agatgaaggt tacgattggt tgattatgac acccggtgtg ggtttagatg 3120 acaagggaga cgcattgggt caacagtata gaaccgtgga tgatgtggtc tctacaggat 3180 ctgacattat tattgttgga agaggactat ttgcaaaggg aagggatgct aaggtagagg 3240 gtgaacgtta cagaaaagca ggctgggaag catatttgag aagatgcggc cagcaaaact 3300 aaaaaactgt attataagta aatgcatgta tactaaactc acaaattaga gcttcaattt 3360 aattatatca gttattaccc tcgacctcga aattcctgca ggatatctgg atcgatccac 3420 aagcttgcat gcctgcaggt cgactctggt cacagtgacc ggtcacagtg accttatgga 3480 agcaccaaga aaaaaggaag ttaaacaaaa cactgattca ataagcaagg ggggaagctc 3540 cttagtttga cgacagtaac aaaatgttcg tataaattga acgaaactca agccaataaa 3600 ggacttttca gaggcctatc tcttctttct ccacaacttt cgaataaaaa ccactaataa 3660 aaagtaaata acaaaaacaa gaaaaaaaat aaacaaaaca ataatcatgg gatccaccat 3720 gattacggat tcactggccg tcgttttaca acgtcgtgac tgggaaaacc ctggcgttac 3780 ccaacttaat cgccttgcag cacatccccc tttcgccagc tggcgtaata gcgaagaggc 3840 ccgcaccgat cgcccttccc aacagttgcg cagcctgaat ggcgaatggc gctttgcctg 3900 gtttccggca ccagaagcgg tgccggaaag ctggctggag tgcgatcttc ctgaggccga 3960 tactgtcgtc gtcccctcaa actggcagat gcacggttac gatgcgccca tctacaccaa 4020 cgtaacctat cccattacgg tcaatccgcc gtttgttccc acggagaatc cgacgggttg 4080 ttactcgctc acatttaatg ttgatgaaag ctggctacag gaaggccaga cgcgaattat 4140 ttttgatggc gttaactcgg cgtttcatct gtggtgcaac gggcgctggg tcggttacgg 4200 ccaggacagt cgtttgccgt ctgaatttga cctgagcgca tttttacgcg ccggagaaaa 4260 ccgcctcgcg gtgatggtgc tgcgttggag tgacggcagt tatctggaag atcaggatat 4320 gtggcggatg agcggcattt tccgtgacgt ctcgttgctg cataaaccga ctacacaaat 4380 cagcgatttc catgttgcca ctcgctttaa tgatgatttc agccgcgctg tactggaggc 4440 tgaagttcag atgtgcggcg agttgcgtga ctacctacgg gtaacagttt ctttatggca 4500 gggtgaaacg caggtcgcca gcggcaccgc gcctttcggc ggtgaaatta tcgatgagcg 4560 tggtggttat gccgatcgcg tcacactacg tctgaacgtc gaaaacccga aactgtggag 4620 cgccgaaatc ccgaatctct atcgtgcggt ggttgaactg cacaccgccg acggcacgct 4680 gattgaagca gaagcctgcg atgtcggttt ccgcgaggtg cggattgaaa atggtctgct 4740 gctgctgaac ggcaagccgt tgctgattcg aggcgttaac cgtcacgagc atcatcctct 4800 gcatggtcag gtcatggatg agcagacgat ggtgcaggat atcctgctga tgaagcagaa 4860 caactttaac gccgtgcgct gttcgcatta tccgaaccat ccgctgtggt acacgctgtg 4920 cgaccgctac ggcctgtatg tggtggatga agccaatatt gaaacccacg gcatggtgcc 4980 aatgaatcgt ctgaccgatg atccgcgctg gctaccggcg atgagcgaac gcgtaacgcg 5040 aatggtgcag cgcgatcgta atcacccgag tgtgatcatc tggtcgctgg ggaatgaatc 5100 aggccacggc gctaatcacg acgcgctgta tcgctggatc aaatctgtcg atccttcccg 5160 cccggtgcag tatgaaggcg gcggagccga caccacggcc accgatatta tttgcccgat 5220 gtacgcgcgc gtggatgaag accagccctt cccggctgtg ccgaaatggt ccatcaaaaa 5280 atggctttcg ctacctggag agacgcgccc gctgatcctt tgcgaatacg cccacgcgat 5340 gggtaacagt cttggcggtt tcgctaaata ctggcaggcg tttcgtcagt atccccgttt 5400 acagggcggc ttcgtctggg actgggtgga tcagtcgctg attaaatatg atgaaaacgg 5460 caacccgtgg tcggcttacg gcggtgattt tggcgatacg ccgaacgatc gccagttctg 5520 tatgaacggt ctggtctttg ccgaccgcac gccgcatcca gcgctgacgg aagcaaaaca 5580 ccagcagcag tttttccagt tccgtttatc cgggcaaacc atcgaagtga ccagcgaata 5640 cctgttccgt catagcgata acgagctcct gcactggatg gtggcgctgg atggtaagcc 5700 gctggcaagc ggtgaagtgc ctctggatgt cgctccacaa ggtaaacagt tgattgaact 5760 gcctgaacta ccgcagccgg agagcgccgg gcaactctgg ctcacagtac gcgtagtgca 5820 accgaacgcg accgcatggt cagaagccgg gcacatcagc gcctggcagc agtggcgtct 5880 ggcggaaaac ctcagtgtga cgctccccgc cgcgtcccac gccatcccgc atctgaccac 5940 cagcgaaatg gatttttgca tcgagctggg taataagcgt tggcaattta accgccagtc 6000 aggctttctt tcacagatgt ggattggcga taaaaaacaa ctgctgacgc cgctgcgcga 6060 tcagttcacc cgtgcaccgc tggataacga cattggcgta agtgaagcga cccgcattga 6120 ccctaacgcc tgggtcgaac gctggaaggc ggcgggccat taccaggccg aagcagcgtt 6180 gttgcagtgc acggcagata cacttgctga tgcggtgctg attacgaccg ctcacgcgtg 6240 gcagcatcag gggaaaacct tatttatcag ccggaaaacc taccggattg atggtagtgg 6300 tcaaatggcg attaccgttg atgttgaagt ggcgagcgat acaccgcatc cggcgcggat 6360 tggcctgaac tgccagctgg cgcaggtagc agagcgggta aactggctcg gattagggcc 6420 gcaagaaaac tatcccgacc gccttactgc cgcctgtttt gaccgctggg atctgccatt 6480 gtcagacatg tataccccgt acgtcttccc gagcgaaaac ggtctgcgct gcgggacgcg 6540 cgaattgaat tatggcccac accagtggcg cggcgacttc cagttcaaca tcagccgcta 6600 cagtcaacag caactgatgg aaaccagcca tcgccatctg ctgcacgcgg aagaaggcac 6660 atggctgaat atcgacggtt tccatatggg gattggtggc gacgactcct ggagcccgtc 6720 agtatcggcg gaattccagc tgagcgccgg tcgctaccat taccagttgg tctggtgtca 6780 aaaataataa taagagctcg aattcgctgc ctcgcgcgtt tcggtgatga cggtgaaaac 6840 ctctgacaca tgcagctccc ggagacggtc acagcttgtc tgtaagcgga tgccgggagc 6900 agacaagccc gtcagggcgc gtcagcgggt gttggcgggt gtcggggcgc agccatgacc 6960 cagtcacgta gcgatagcgg agtgtatact ggcttaacta tgcggcatca gagcagattg 7020 tactgagagt gcaccatatg cggtgtgaaa taccgcacag atgcgtaagg agaaaatacc 7080 gcatcaggcg ctcttccgct tcctcgctca ctgactcgct gcgctcggtc gttcggctgc 7140 ggcgagcggt atcagctcac tcaaaggcgg taatacggtt atccacagaa tcaggggata 7200 acgcaggaaa gaacatgtga gcaaaaggcc agcaaaaggc caggaaccgt aaaaaggccg 7260 cgttgctggc gtttttccat aggctccgcc cccctgacga gcatcacaaa aatcgacgct 7320 caagtcagag gtggcgaaac ccgacaggac tataaagata ccaggcgttt ccccctggaa 7380 gctccctcgt gcgctctcct gttccgaccc tgccgcttac cggatacctg tccgcctttc 7440 tcccttcggg aagcgtggcg ctttctcata gctcacgctg taggtatctc agttcggtgt 7500 aggtcgttcg ctccaagctg ggctgtgtgc acgaaccccc cgttcagccc gaccgctgcg 7560 ccttatccgg taactatcgt cttgagtcca acccggtaag acacgactta tcgccactgg 7620 cagcagccac tggtaacagg attagcagag cgaggtatgt aggcggtgct acagagttct 7680 tgaagtggtg gcctaactac ggctacacta gaaggacagt atttggtatc tgcgctctgc 7740 tgaagccagt taccttcgga aaaagagttg gtagctcttg atccggcaaa caaaccaccg 7800 ctggtagcgg tggttttttt gtttgcaagc agcagattac gcgcagaaaa aaaggatctc 7860 aagaagatcc tttgatcttt tctacggggt ctgacgctca gtggaacgaa aactcacgtt 7920 aagggatttt ggtcatgaga ttatcaaaaa ggatcttcac ctagatcctt ttaaattaaa 7980 aatgaagttt taaatcaatc taaagtatat atgagtaaac ttggtctgac agttaccaat 8040 gcttaatcag tgaggcacct atctcagcga tctgtctatt tcgttcatcc atagttgcct 8100 gactccccgt cgtgtagata actacgatac gggagggctt accatctggc cccagtgctg 8160 caatgatacc gcgagaccca cgctcaccgg ctccagattt atcagcaata aaccagccag 8220 ccggaagggc cgagcgcaga agtggtcctg caactttatc cgcctccatc cagtctatta 8280 attgttgccg ggaagctaga gtaagtagtt cgccagttaa tagtttgcgc aacgttgttg 8340 ccattgctgc aggcatcgtg gtgtcacgct cgtcgtttgg tatggcttca ttcagctccg 8400 gttcccaacg atcaaggcga gttacatgat cccccatgtt gtgcaaaaaa gcggttagct 8460 ccttcggtcc tccgatcgtt gtcagaagta agttggccgc agtgttatca ctcatggtta 8520 tggcagcact gcataattct cttactgtca tgccatccgt aagatgcttt tctgtgactg 8580 gtgagtactc aaccaagtca ttctgagaat agtgtatgcg gcgaccgagt tgctcttgcc 8640 cggcgtcaac acgggataat accgcgccac atagcagaac tttaaaagtg ctcatcattg 8700 gaaaacgttc ttcggggcga aaactctcaa ggatcttacc gctgttgaga tccagttcga 8760 tgtaacccac tcgtgcaccc aactgatctt cagcatcttt tactttcacc agcgtttctg 8820 ggtgagcaaa aacaggaagg caaaatgccg caaaaaaggg aataagggcg acacggaaat 8880 gttgaatact catactcttc ctttttcaat attattgaag catttatcag ggttattgtc 8940 tcatgagcgg atacatattt gaatgtattt agaaaaataa acaaataggg gttccgcgca 9000 catttccccg aaaagtgcca cctgacgtct aagaaaccat tattatcatg acattaacct 9060 ataaaaatag gcgtatcacg aggccctttc gtcttcaa 9098 9 7979 DNA Artificial Sequence yeast expression vector for human estrogen receptor alpha 9 ggatcccatt accgacattt gggcgctata cgtgcatatg ttcatgtatg tatctgtatt 60 taaaacactt ttgtattatt tttcctcata tatgtgtata ggtttatacg gatgatttaa 120 ttattacttc accacccttt atttcaggct gatatcttag ccttgttact agttagaaaa 180 agacattttt gctgtcagtc actgtcaaga gattcttttg ctggcatttc ttctagaagc 240 aaaaagagcg atgcgtcttt tccgctgaac cgttccagca aaaaagacta ccaacgcaat 300 atggattgtc agaatcatat aaaagagaag caaataactc cttgtcttgt atcaattgca 360 ttataatatc ttcttgttag tgcaatatca tatagaagtc atcgaaatag atattaagaa 420 aaacaaactg taacgaattc attatgcaga tcttcgtcaa gacgttaacc ggtaaaacca 480 taactctaga agttgaatct tccgatacca tcgacaacgt taagtcgaaa attcaagaca 540 aggaaggcat tccacctgat caacaaagat tgatctttgc cggtaagcag ctcgaggacg 600 gtagaacgct gtctgattac aacattcaga aggagtcgac cttacatctt gtcttaagac 660 taagaggtgg tatgaccatg accctccaca ccaaagcatc tgggatggcc ctactgcatc 720 agatccaagg gaacgagctg gagcccctga accgtccgca gctcaagatc cccctggagc 780 ggcccctggg cgaggtgtac ctggacagca gcaagcccgc cgtgtacaac taccccgagg 840 gcgccgccta cgagttcaac gccgcggccg ccgccaacgc gcaggtctac ggtcagaccg 900 gcctccccta cggccccggg tctgaggctg cggcgttcgg ctccaacggc ctggggggtt 960 tccccccact caacagcgtg tctccgagcc cgctgatgct actgcacccg ccgccgcagc 1020 tgtcgccttt cctgcagccc cacggccagc aggtgcccta ctacctggag aacgagccca 1080 gcggctacac ggtgcgcgag gccggcccgc cggcattcta caggccaaat tcagataatc 1140 gacgccaggg tggcagagaa agattggcca gtaccaatga caagggaagt atggctatgg 1200 aatctgccaa ggagactcgc tactgtgcag tgtgcaatga ctatgcttca ggctaccatt 1260 atggagtctg gtcctgtgag ggctgcaagg ccttcttcaa gagaagtatt caaggacata 1320 acgactatat gtgtccagcc accaaccagt gcaccattga taaaaacagg aggaagagct 1380 gccaggcctg ccggctccgc aaatgctacg aagtgggaat gatgaaaggt gggatacgaa 1440 aagaccgaag aggagggaga atgttgaaac acaagcgcca gagagatgat ggggagggca 1500 ggggtgaagt ggggtctgct ggagacatga gagctgccaa cctttggcca agcccgctca 1560 tgatcaaacg ctctaagaag aacagcctgg ccttgtccct gacggccgac cagatggtca 1620 gtgccttgtt ggatgctgag ccccccatac tctattccga gtatgatcct accagaccct 1680 tcagtgaagc ttcgatgatg ggcttactga ccaacctggc agacagggag ctggttcaca 1740 tgatcaactg ggcgaagagg gtgccaggct ttgtggattt gaccctccat gatcaggtcc 1800 accttctaga atgtgcctgg ctagagatcc tgatgattgg tctcgtctgg cgctccatgg 1860 agcacccagt gaagctactg tttgctccta acttgctctt ggacaggaac cagggaaaat 1920 gtgtagaggg catggtggag atcttcgaca tgctgctggc tacatcatct cggttccgca 1980 tgatgaatct gcagggagag gagtttgtgt gcctcaaatc tattattttg cttaattctg 2040 gagtgtacac atttctgtcc agcaccctga agtctctgga agagaaggac catatccacc 2100 gagtcctgga caagatcaca gacactttga tccacctgat ggccaaggca ggcctgaccc 2160 tgcagcagca gcaccagcgg ctggcccagc tcctcctcat cctctcccac atcaggcaca 2220 tgagtaacaa aggcatggag catctgtaca gcatgaagtg caagaacgtg gtgcccctct 2280 atgacctgct gctggagatg ctggacgccc accgcctaca tgcgcccact agccgtggag 2340 gggcatccgt ggaggagacg gaccaaagcc acttggccac tgcgggctct acttcatcgc 2400 attccttgca aaagtattac atcacggggg aggcagaggg tttccctgcc acagtctgag 2460 agctccctgg cgaattgtac caagatggcc tttggtgggt tgaagaagga aaaagacaga 2520 aacgacttaa ttacctactt gaaaaaagcc tgtgagtaaa caggcccctt ttcctttgtc 2580 gatatcatgt aattagttat gtcacgctta cattcacgcc ctccccccac atccgctcta 2640 accgaaaagg aaggagttag acaacctgaa gtctaggtcc ctatttattt ttttatagtt 2700 atgttagtat taagaacgtt atttatattt caaatttttc ttttttttct gtacagacgc 2760 gtgtacgcat gtaacattat actgaaaacc ttgcttgaga aggttttggg acgctcgaag 2820 gctttaattt gcaagcttat cgatgataag ctgtcaaaca tgagaattcg gtcgaaaaaa 2880 gaaaaggaga gggccaagag ggagggcatt ggtgactatt gagcacgtga gtatacgtga 2940 ttaagcacac aaaggcagct tggagtatgt ctgttattaa tttcacaggt agttctggtc 3000 cattggtgaa agtttgcggc ttgcagagca cagaggccgc agaatgtgct ctagattccg 3060 atgctgactt gctgggtatt atatgtgtgc ccaatagaaa gagaacaatt gacccggtta 3120 ttgcaaggaa aatttcaagt cttgtaaaag catataaaaa tagttcaggc actccgaaat 3180 acttggttgg cgtgtttcgt aatcaaccta aggaggatgt tttggctctg gtcaatgatt 3240 acggcattga tatcgtccaa ctgcatggag atgagtcgtg gcaagaatac caagagttcc 3300 tcggtttgcc agttattaaa agactcgtat ttccaaaaga ctgcaacata ctactcagtg 3360 cagcttcaca gaaacctcat tcgtttattc ccttgtttga ttcagaagca ggtgggacag 3420 gtgaactttt ggattggaac tcgatttctg actgggttgg aaggcaagag agccccgaaa 3480 gcttacattt tatgttagct ggtggactga cgccagaaaa tgttggtgat gcgcttagat 3540 taaatggcgt tattggtgtt gatgtaagcg gaggtgtgga gacaaatggt gtaaaagact 3600 ctaacaaaat agcaaatttc gtcaaaaatg ctaagaaata ggttattact gagtagtatt 3660 tatttaagta ttgtttgtgc acttgcctgc agcttctcaa tgatattcga atacgctttg 3720 aggagataca gcctaatatc cgacaaactg ttttacagat ttacgatcgt acttgttacc 3780 catcattgaa ttttgaacat ccgaacctgg gagttttccc tgaaacagat agtatatttg 3840 aacctgtata ataatatata gtctagcgct ttacggaaga caatgtatgt atttcggttc 3900 ctggagaaac tattgcatct attgcatagg taatcttgca cgtcgcatcc ccggttcatt 3960 ttctgcgttt ccatcttgca cttcaatagc atatctttgt taacgaagca tctgtgcttc 4020 attttgtaga acaaaaatgc aacgcgagag cgctaatttt tcaaacaaag aatctgagct 4080 gcatttttac agaacagaaa tgcaacgcga aagcgctatt ttaccaacga agaatctgtg 4140 cttcattttt gtaaaacaaa aatgcaacgc gagagcgcta atttttcaaa caaagaatct 4200 gagctgcatt tttacagaac agaaatgcaa cgcgagagcg ctattttacc aacaaagaat 4260 ctatacttct tttttgttct acaaaaatgc atcccgagag cgctattttt ctaacaaagc 4320 atcttagatt actttttttc tcctttgtgc gctctataat gcagtctctt gataactttt 4380 tgcactgtag gtccgttaag gttagaagaa ggctactttg gtgtctattt tctcttccat 4440 aaaaaaagcc tgactccact tcccgcgttt actgattact agcgaagctg cgggtgcatt 4500 ttttcaagat aaaggcatcc ccgattatat tctataccga tgtggattgc gcatactttg 4560 tgaacagaaa gtgatagcgt tgatgattct tcattggtca gaaaattatg aacggtttct 4620 tctattttgt ctctatatac tacgtatagg aaatgtttac attttcgtat tgttttcgat 4680 tcactctatg aatagttctt actacaattt ttttgtctaa agagtaatac tagagataaa 4740 cataaaaaat gtagaggtcg agtttagatg caagttcaag gagcgaaagg tggatgggta 4800 ggttatatag ggatatagca cagagatata tagcaaagag atacttttga gcaatgtttg 4860 tggaagcggt attcgcaata ttttagtagc tcgttacagt ccggtgcgtt tttggttttt 4920 tgaaagtgcg tcttcagagc gcttttggtt ttcaaaagcg ctctgaagtt cctatacttt 4980 ctagagaata ggaacttcgg aataggaact tcaaagcgtt tccgaaaacg agcgcttccg 5040 aaaatgcaac gcgagctgcg cacatacagc tcactgttca cgtcgcacct atatctgcgt 5100 gttgcctgta tatatatata catgagaaga acggcatagt gcgtgtttat gcttaaatgc 5160 gtacttatat gcgtctattt atgtaggatg aaaggtagtc tagtacctcc tgtgatatta 5220 tcccattcca tgcggggtat cgtatgcttc cttcagcact accctttagc tgttctatat 5280 gctgccactc ctcaattgga ttagtctcat ccttcaatgc tatcatttcc tttgatattg 5340 gatcatatgc atagtaccga gaaactagtg cgaagtagtg atcaggtatt gctgttatct 5400 gatgagtata cgttgtcctg gccacggcag aagcacgctt atcgctccaa tttcccacaa 5460 cattagtcaa ctccgttagg cccttcattg aaagaaatga ggtcatcaaa tgtcttccaa 5520 tgtgagattt tgggccattt tttatagcaa agattgaata aggcgcattt ttcttcaaag 5580 ctttattgta cgatctgact aagttatctt ttaataattg gtattcctgt ttattgcttg 5640 aagaattgcc ggtcctattt actcgtttta ggactggttc agaattcttg aagacgaaag 5700 ggcctcgtga tacgcctatt tttataggtt aatgtcatga taataatggt ttcttagacg 5760 tcaggtggca cttttcgggg aaatgtgcgc ggaaccccta tttgtttatt tttctaaata 5820 cattcaaata tgtatccgct catgagacaa taaccctgat aaatgcttca ataatattga 5880 aaaaggaaga gtatgagtat tcaacatttc cgtgtcgccc ttattccctt ttttgcggca 5940 ttttgccttc ctgtttttgc tcacccagaa acgctggtga aagtaaaaga tgctgaagat 6000 cagttgggtg cacgagtggg ttacatcgaa ctggatctca acagcggtaa gatccttgag 6060 agttttcgcc ccgaagaacg ttttccaatg atgagcactt ttaaagttct gctatgtggc 6120 gcggtattat cccgtgttga cgccgggcaa gagcaactcg gtcgccgcat acactattct 6180 cagaatgact tggttgagta ctcaccagtc acagaaaagc atcttacgga tggcatgaca 6240 gtaagagaat tatgcagtgc tgccataacc atgagtgata acactgcggc caacttactt 6300 ctgacaacga tcggaggacc gaaggagcta accgcttttt tgcacaacat gggggatcat 6360 gtaactcgcc ttgatcgttg ggaaccggag ctgaatgaag ccataccaaa cgacgagcgt 6420 gacaccacga tgcctgcagc aatggcaaca acgttgcgca aactattaac tggcgaacta 6480 cttactctag cttcccggca acaattaata gactggatgg aggcggataa agttgcagga 6540 ccacttctgc gctcggccct tccggctggc tggtttattg ctgataaatc tggagccggt 6600 gagcgtgggt ctcgcggtat cattgcagca ctggggccag atggtaagcc ctcccgtatc 6660 gtagttatct acacgacggg gagtcaggca actatggatg aacgaaatag acagatcgct 6720 gagataggtg cctcactgat taagcattgg taactgtcag accaagttta ctcatatata 6780 ctttagattg atttaaaact tcatttttaa tttaaaagga tctaggtgaa gatccttttt 6840 gataatctca tgaccaaaat cccttaacgt gagttttcgt tccactgagc gtcagacccc 6900 gtagaaaaga tcaaaggatc ttcttgagat cctttttttc tgcgcgtaat ctgctgcttg 6960 caaacaaaaa aaccaccgct accagcggtg gtttgtttgc cggatcaaga gctaccaact 7020 ctttttccga aggtaactgg cttcagcaga gcgcagatac caaatactgt ccttctagtg 7080 tagccgtagt taggccacca cttcaagaac tctgtagcac cgcctacata cctcgctctg 7140 ctaatcctgt taccagtggc tgctgccagt ggcgataagt cgtgtcttac cgggttggac 7200 tcaagacgat agttaccgga taaggcgcag cggtcgggct gaacgggggg ttcgtgcaca 7260 cagcccagct tggagcgaac gacctacacc gaactgagat acctacagcg tgagctatga 7320 gaaagcgcca cgcttcccga agggagaaag gcggacaggt atccggtaag cggcagggtc 7380 ggaacaggag agcgcacgag ggagcttcca gggggaaacg cctggtatct ttatagtcct 7440 gtcgggtttc gccacctctg acttgagcgt cgatttttgt gatgctcgtc aggggggcgg 7500 agcctatgga aaaacgccag caacgcggcc tttttacggt tcctggcctt ttgctggcct 7560 tttgctcaca tgttctttcc tgcgttatcc cctgattctg tggataaccg tattaccgcc 7620 tttgagtgag ctgataccgc tcgccgcagc cgaacgaccg agcgcagcga gtcagtgagc 7680 gaggaagcgg aagagcgcct gatgcggtat tttctcctta cgcatctgtg cggtatttca 7740 caccgcatat ggtgcactct cagtacaatc tgctctgatg ccgcatagtt aagccagtat 7800 acactccgct atcgctacgt gactgggtca tggctgcgcc ccgacacccg ccaacacccg 7860 ctgacgcgcc ctgacgggct tgtctgctcc cggcatccgc ttacagacaa gctgtgaccg 7920 tctccgggag ctgcatgtgt cagaggtttt caccgtcatc accgaaacgc gcgaggcag 7979 10 9952 DNA Artificial Sequence yeast expression vector for the E. coli glucuronidase gene pRS425-GPD-UbGUS 10 gacgaaaggg cctcgtgata cgcctatttt tataggttaa tgtcatgata ataatggttt 60 cttagtatga tccaatatca aaggaaatga tagcattgaa ggatgagact aatccaattg 120 aggagtggca gcatatagaa cagctaaagg gtagtgctga aggaagcata cgataccccg 180 catggaatgg gataatatca caggaggtac tagactacct ttcatcctac ataaatagac 240 gcatataagt acgcatttaa gcataaacac gcactatgcc gttcttctca tgtatatata 300 tatacaggca acacgcagat ataggtgcga cgtgaacagt gagctgtatg tgcgcagctc 360 gcgttgcatt ttcggaagcg ctcgttttcg gaaacgcttt gaagttccta ttccgaagtt 420 cctattctct agaaagtata ggaacttcag agcgcttttg aaaaccaaaa gcgctctgaa 480 gacgcacttt caaaaaacca aaaacgcacc ggactgtaac gagctactaa aatattgcga 540 ataccgcttc cacaaacatt gctcaaaagt atctctttgc tatatatctc tgtgctatat 600 ccctatataa cctacccatc cacctttcgc tccttgaact tgcatctaaa ctcgacctct 660 acatttttta tgtttatctc tagtattact ctttagacaa aaaaattgta gtaagaacta 720 ttcatagagt gaatcgaaaa caatacgaaa atgtaaacat ttcctatacg tagtatatag 780 agacaaaata gaagaaaccg ttcataattt tctgaccaat gaagaatcat caacgctatc 840 actttctgtt cacaaagtat gcgcaatcca catcggtata gaatataatc ggggatgcct 900 ttatcttgaa aaaatgcacc cgcagcttcg ctagtaatca gtaaacgcgg gaagtggagt 960 caggcttttt ttatggaaga gaaaatagac accaaagtag ccttcttcta accttaacgg 1020 acctacagtg caaaaagtta tcaagagact gcattataga gcgcacaaag gagaaaaaaa 1080 gtaatctaag atgctttgtt agaaaaatag cgctctcggg atgcattttt gtagaacaaa 1140 aaagaagtat agattctttg ttggtaaaat agcgctctcg cgttgcattt ctgttctgta 1200 aaaatgcagc tcagattctt tgtttgaaaa attagcgctc tcgcgttgca tttttgtttt 1260 acaaaaatga agcacagatt cttcgttggt aaaatagcgc tttcgcgttg catttctgtt 1320 ctgtaaaaat gcagctcaga ttctttgttt gaaaaattag cgctctcgcg ttgcattttt 1380 gttctacaaa atgaagcaca gatgcttcgt tcaggtggca cttttcgggg aaatgtgcgc 1440 ggaaccccta tttgtttatt tttctaaata cattcaaata tgtatccgct catgagacaa 1500 taaccctgat aaatgcttca ataatattga aaaaggaaga gtatgagtat tcaacatttc 1560 cgtgtcgccc ttattccctt ttttgcggca ttttgccttc ctgtttttgc tcacccagaa 1620 acgctggtga aagtaaaaga tgctgaagat cagttgggtg cacgagtggg ttacatcgaa 1680 ctggatctca acagcggtaa gatccttgag agttttcgcc ccgaagaacg ttttccaatg 1740 atgagcactt ttaaagttct gctatgtggc gcggtattat cccgtattga cgccgggcaa 1800 gagcaactcg gtcgccgcat acactattct cagaatgact tggttgagta ctcaccagtc 1860 acagaaaagc atcttacgga tggcatgaca gtaagagaat tatgcagtgc tgccataacc 1920 atgagtgata acactgcggc caacttactt ctgacaacga tcggaggacc gaaggagcta 1980 accgcttttt tgcacaacat gggggatcat gtaactcgcc ttgatcgttg ggaaccggag 2040 ctgaatgaag ccataccaaa cgacgagcgt gacaccacga tgcctgtagc aatggcaaca 2100 acgttgcgca aactattaac tggcgaacta cttactctag cttcccggca acaattaata 2160 gactggatgg aggcggataa agttgcagga ccacttctgc gctcggccct tccggctggc 2220 tggtttattg ctgataaatc tggagccggt gagcgtgggt ctcgcggtat cattgcagca 2280 ctggggccag atggtaagcc ctcccgtatc gtagttatct acacgacggg gagtcaggca 2340 actatggatg aacgaaatag acagatcgct gagataggtg cctcactgat taagcattgg 2400 taactgtcag accaagttta ctcatatata ctttagattg atttaaaact tcatttttaa 2460 tttaaaagga tctaggtgaa gatccttttt gataatctca tgaccaaaat cccttaacgt 2520 gagttttcgt tccactgagc gtcagacccc gtagaaaaga tcaaaggatc ttcttgagat 2580 cctttttttc tgcgcgtaat ctgctgcttg caaacaaaaa aaccaccgct accagcggtg 2640 gtttgtttgc cggatcaaga gctaccaact ctttttccga aggtaactgg cttcagcaga 2700 gcgcagatac caaatactgt ccttctagtg tagccgtagt taggccacca cttcaagaac 2760 tctgtagcac cgcctacata cctcgctctg ctaatcctgt taccagtggc tgctgccagt 2820 ggcgataagt cgtgtcttac cgggttggac tcaagacgat agttaccgga taaggcgcag 2880 cggtcgggct gaacgggggg ttcgtgcaca cagcccagct tggagcgaac gacctacacc 2940 gaactgagat acctacagcg tgagctatga gaaagcgcca cgcttcccga agggagaaag 3000 gcggacaggt atccggtaag cggcagggtc ggaacaggag agcgcacgag ggagcttcca 3060 gggggaaacg cctggtatct ttatagtcct gtcgggtttc gccacctctg acttgagcgt 3120 cgatttttgt gatgctcgtc aggggggcgg agcctatgga aaaacgccag caacgcggcc 3180 tttttacggt tcctggcctt ttgctggcct tttgctcaca tgttctttcc tgcgttatcc 3240 cctgattctg tggataaccg tattaccgcc tttgagtgag ctgataccgc tcgccgcagc 3300 cgaacgaccg agcgcagcga gtcagtgagc gaggaagcgg aagagcgccc aatacgcaaa 3360 ccgcctctcc ccgcgcgttg gccgattcat taatgcagct ggcacgacag gtttcccgac 3420 tggaaagcgg gcagtgagcg caacgcaatt aatgtgagtt acctcactca ttaggcaccc 3480 caggctttac actttatgct tccggctcct atgttgtgtg gaattgtgag cggataacaa 3540 tttcacacag gaaacagcta tgaccatgat tacgccaagc gcgcaattaa ccctcactaa 3600 agggaacaaa agctggagct cgtttatcat tatcaatact cgccatttca aagaatacgt 3660 aaataattaa tagtagtgat tttcctaact ttatttagtc aaaaaattag ccttttaatt 3720 ctgctgtaac ccgtacatgc caaaataggg ggcgggttac acagaatata taacactgat 3780 ggtgcttggg tgaacaggtt tattcctggc atccactaaa tataatggag cccgcttttt 3840 aagctggcat ccagaaaaaa aaagaatccc agcaccaaaa tattgttttc ttcaccaacc 3900 atcagttcat aggtccattc tcttagcgca actacagaga acagggcaca aacaggcaaa 3960 aaacgggcac aacctcaatg gagtgatgca acctgcctgg agtaaatgat gacacaaggc 4020 aattgaccca cgcatgtatc tatctcattt tcttacacct tctattacct tctgctctct 4080 ctgatttgga aaaagctgaa aaaaaaggtt taaaccagtt ccctgaaatt attcccctac 4140 ttgactaata agtatataaa gacggtaggt attgattgta attctgtaaa tctatttctt 4200 aaacttctta aattctactt ttatagttag tctttttttt agttttaaaa caccaagaac 4260 ttagtttcga cggattctag aactagtgga tccaagaatt cattatgcag atcttcgtca 4320 agacgttaac cggtaaaacc ataactctag aagttgaatc ttccgatacc atcgacaacg 4380 ttaagtcgaa aattcaagac aaggaaggca ttccacctga tcaacaaaga ttgatctttg 4440 ccggtaagca gctcgaggac ggtagaacgc tgtctgatta caacattcag aaggagtcga 4500 ccttacatct tgtcttaaga ctaagaggtg gtatggaatt catgttacgt cctgtagaaa 4560 ccccaacccg tgaaatcaaa aaactcgacg gcctgtgggc attcagtctg gatcgcgaaa 4620 actgtggaat tgatcagcgt tggtgggaaa gcgcgttaca agaaagccgg gcaattgctg 4680 tgccaggcag ttttaacgat cagttcgccg atgcagatat tcgtaattat gcgggcaacg 4740 tctggtatca gcgcgaagtc tttataccga aaggttgggc aggccagcgt atcgtgctgc 4800 gtttcgatgc ggtcactcat tacggcaaag tgtgggtcaa taatcaggaa gtgatggagc 4860 atcagggcgg ctatacgcca tttgaagccg atgtcacgcc gtatgttatt gccgggaaaa 4920 gtgtacgtat caccgtttgt gtgaacaacg aactgaactg gcagactatc ccgccgggaa 4980 tggtgattac cgacgaaaac ggcaagaaaa agcagtctta cttccatgat ttctttaact 5040 atgccggaat ccatcgcagc gtaatgctct acaccacgcc gaacacctgg gtggacgata 5100 tcaccgtggt gacgcatgtc gcgcaagact gtaaccacgc gtctgttgac tggcaggtgg 5160 tggccaatgg tgatgtcagc gttgaactgc gtgatgcgga tcaacaggtg gttgcaactg 5220 gacaaggcac tagcgggact ttgcaagtgg tgaatccgca cctctggcaa ccgggtgaag 5280 gttatctcta tgaactgtgc gtcacagcca aaagccagac agagtgtgat atctacccgc 5340 ttcgcgtcgg catccggtca gtggcagtga agggccaaca gttcctgatt aaccacaaac 5400 cgttctactt tactggcttt ggtcgtcatg aagatgcgga cttacgtggc aaaggattcg 5460 ataacgtgct gatggtgcac gaccacgcat taatggactg gattggggcc aactcctacc 5520 gtacctcgca ttacccttac gctgaagaga tgctcgactg ggcagatgaa catggcatcg 5580 tggtgattga tgaaactgct gctgtcggct ttaacctctc tttaggcatt ggtttcgaag 5640 cgggcaacaa gccgaaagaa ctgtacagcg aagaggcagt caacggggaa actcagcaag 5700 cgcacttaca ggcgattaaa gagctgatag cgcgtgacaa aaaccaccca agcgtggtga 5760 tgtggagtat tgccaacgaa ccggataccc gtccgcaagt gcacgggaat atttcgccac 5820 tggcggaagc aacgcgtaaa ctcgacccga cgcgtccgat cacctgcgtc aatgtaatgt 5880 tctgcgacgc tcacaccgat accatcagcg atctctttga tgtgctgtgc ctgaaccgtt 5940 attacggatg gtatgtccaa agcggcgatt tggaaacggc agagaaggta ctggaaaaag 6000 aacttctggc ctggcaggag aaactgcatc agccgattat catcaccgaa tacggcgtgg 6060 atacgttagc cgggctgcac tcaatgtaca ccgacatgtg gagtgaagag tatcagtgtg 6120 catggctgga tatgtatcac cgcgtctttg atcgcgtcag cgccgtcgtc ggtgaacagg 6180 tatggaattt cgccgatttt gcgacctcgc aaggcatatt gcgcgttggc ggtaacaaga 6240 aagggatctt cactcgcgac cgcaaaccga agtcggcggc ttttctgctg caaaaacgct 6300 ggactggcat gaacttcggt gaaaaaccgc agcagggagg caaacaatga gaatcccatc 6360 aagcttatcg ataccgtcga cctcgagtgc aaattaaagc cttcgagcgt cccaaaacct 6420 tctcaagcaa ggttttcagt ataatgttac atgcgtacac gcgtctgtac agaaaaaaaa 6480 gaaaaatttg aaatataaat aacgttctta atactaacat aactataaaa aaataaatag 6540 ggacctagac ttcaggttgt ctaactcctt ccttttcggt tagagcggat gtggggggag 6600 ggcgtgaatg taagcgtgac ataactaatt acatggtacc caattcgccc tatagtgagt 6660 cgtattacgc gcgctcactg gccgtcgttt tacaacgtcg tgactgggaa aaccctggcg 6720 ttacccaact taatcgcctt gcagcacatc cccctttcgc caggggctgc aggaattcga 6780 tatcaagctt atcgataccg tcgacctcga gggggggccc ggtacccaat tcgccctata 6840 gtgagtcgta ttacgcgcgc tcactggccg tcgttttaca acgtcgtgac tgggaaaacc 6900 ctggcgttac ccaacttaat cgccttgcag cacatccccc tttcgccagc tggcgtaata 6960 gcgaagaggc ccgcaccgat cgcccttccc aacagttgcg cagcctgaat ggcgaatggc 7020 gcgacgcgcc ctgtagcggc gcattaagcg cggcgggtgt ggtggttacg cgcagcgtga 7080 ccgctacact tgccagcgcc ctagcgcccg ctcctttcgc tttcttccct tcctttctcg 7140 ccacgttcgc cggctttccc cgtcaagctc taaatcgggg gctcccttta gggttccgat 7200 ttagtgcttt acggcacctc gaccccaaaa aacttgatta gggtgatggt tcacgtagtg 7260 ggccatcgcc ctgatagacg gtttttcgcc ctttgacgtt ggagtccacg ttctttaata 7320 gtggactctt gttccaaact ggaacaacac tcaaccctat ctcggtctat tcttttgatt 7380 tataagggat tttgccgatt tcggcctatt ggttaaaaaa tgagctgatt taacaaaaat 7440 ttaacgcgaa ttttaacaaa atattaacgt ttacaatttc ctgatgcggt attttctcct 7500 tacgcatctg tgcggtattt cacaccgcat atcgacggtc gaggagaact tctagtatat 7560 ccacatacct aatattattg ccttattaaa aatggaatcc caacaattac atcaaaatcc 7620 acattctctt caaaatcaat tgtcctgtac ttccttgttc atgtgtgttc aaaaacgtta 7680 tatttatagg ataattatac tctatttctc aacaagtaat tggttgtttg gccgagcggt 7740 ctaaggcgcc tgattcaaga aatatcttga ccgcagttaa ctgtgggaat actcaggtat 7800 cgtaagatgc aagagttcga atctcttagc aaccattatt tttttcctca acataacgag 7860 aacacacagg ggcgctatcg cacagaatca aattcgatga ctggaaattt tttgttaatt 7920 tcagaggtcg cctgacgcat ataccttttt caactgaaaa attgggagaa aaaggaaagg 7980 tgagaggccg gaaccggctt ttcatataga atagagaagc gttcatgact aaatgcttgc 8040 atcacaatac ttgaagttga caatattatt taaggaccta ttgttttttc caataggtgg 8100 ttagcaatcg tcttactttc taacttttct taccttttac atttcagcaa tatatatata 8160 tatttcaagg atataccatt ctaatgtctg cccctatgtc tgcccctaag aagatcgtcg 8220 ttttgccagg tgaccacgtt ggtcaagaaa tcacagccga agccattaag gttcttaaag 8280 ctatttctga tgttcgttcc aatgtcaagt tcgatttcga aaatcattta attggtggtg 8340 ctgctatcga tgctacaggt gtcccacttc cagatgaggc gctggaagcc tccaagaagg 8400 ttgatgccgt tttgttaggt gctgtggctg gtcctaaatg gggtaccggt agtgttagac 8460 ctgaacaagg tttactaaaa atccgtaaag aacttcaatt gtacgccaac ttaagaccat 8520 gtaactttgc atccgactct cttttagact tatctccaat caagccacaa tttgctaaag 8580 gtactgactt cgttgttgtc agagaattag tgggaggtat ttactttggt aagagaaagg 8640 aagacgatgg tgatggtgtc gcttgggata gtgaacaata caccgttcca gaagtgcaaa 8700 gaatcacaag aatggccgct ttcatggccc tacaacatga gccaccattg cctatttggt 8760 ccttggataa agctaatctt ttggcctctt caagattatg gagaaaaact gtggaggaaa 8820 ccatcaagaa cgaattccct acattgaagg ttcaacatca attgattgat tctgccgcca 8880 tgatcctagt taagaaccca acccacctaa atggtattat aatcaccagc aacatgtttg 8940 gtgatatcat ctccgatgaa gcctccgtta tcccaggttc cttgggtttg ttgccatctg 9000 cgtccttggc ctctttgcca gacaagaaca ccgcatttgg tttgtacgaa ccatgccacg 9060 gttctgctcc agatttgcca aagaataagg ttgaccctat cgccactatc ttgtctgctg 9120 caatgatgtt gaaattgtca ttgaacttgc ctgaagaagg taaggccatt gaagatgcag 9180 ttaaaaaggt tttggatgca ggtatcagaa ctggtgattt aggtggttcc aacagtacca 9240 ccgaagtcgg tgatgctgtc gccgaagaag ttaagaaaat ccttgcttaa aaagattctc 9300 tttttttatg atatttgtac ataaacttta taaatgaaat tcataataga aacgacacga 9360 aattacaaaa tggaatatgt tcatagggta gacgaaacta tatacgcaat ctacatacat 9420 ttatcaagaa ggagaaaaag gaggatagta aaggaataca ggtaagcaaa ttgatactaa 9480 tggctcaacg tgataaggaa aaagaattgc actttaacat taatattgac aaggaggagg 9540 gcaccacaca aaaagttagg tgtaacagaa aatcatgaaa ctacgattcc taatttgata 9600 ttggaggatt ttctctaaaa aaaaaaaaat acaacaaata aaaaacactc aatgacctga 9660 ccatttgatg gagtttaagt caataccttc ttgaagcatt tcccataatg gtgaaagttc 9720 cctcaagaat tttactctgt cagaaacggc cttacgacgt agtcgatatg gtgcactctc 9780 agtacaatct gctctgatgc cgcatagtta agccagcccc gacacccgcc aacacccgct 9840 gacgcgccct gacgggcttg tctgctcccg gcatccgctt acagacaagc tgtgaccgtc 9900 tccgggagct gcatgtgtca gaggttttca ccgtcatcac cgaaacgcgc ga 9952 

What is claimed is:
 1. A ligand dependent transactivation system for gender-sorting in a test animal, comprising; a) a first DNA construct comprising a nucleic acid molecule encoding a receptor having specific binding affinity for said ligand operably linked to a promoter; b) a second DNA construct comprising a promoter containing a plurality of ligand specific response elements, said promoter being operably linked to a reporter gene; c) a third DNA construct comprising a nucleic acid sequence encoding an enzyme for cleaving a naturally occurring biological conjugate, said biological conjugate comprising said ligand, said nucleic acid sequence encoding said enzyme being operably linked to a promoter sequence; and d) a host cell comprising said first, second and third DNA constructs, expression of said reporter gene in said host cell being dependent upon cleavage of said ligand from a biological conjugate present in a biological sample isolated from said test animal, reporter gene expression being indicative of the presence of a ligand which indicates the sex of said test animal.
 2. A system as claimed in claim 1, wherein said first DNA construct encodes a receptor selected from the group of sex related nuclear receptors consisting of estrogen receptor alpha, estrogen receptor beta, androgen receptor, progesterone receptor, glucocorticoid receptor, adrenocorticoid receptor, thyroid hormone receptor alpha and beta, retinoic acid receptor alpha, beta and gamma, retinoic acid X receptor alpha, beta and gamma, peroxysome proliferator activating receptor alpha, delta and gamma, vitamin D receptor, dioxin receptor, and liver X receptor.
 3. A system as claimed in claim 1 wherein said test animal is selected from the group consisting of chickens and turkeys.
 4. A system as claimed in claim 1, wherein said third construct encodes an enzyme selected from the group consisting of beta-glucuronidase, alpha-glucuronidase, sulfatases, SUMO specific proteases, SUMO specific hydrolases, and cytochrome P450 enzymes.
 5. A system as claimed in claim 1, wherein said biological conjugate is selected from the group of conjugates consisting of estrone-sulfate, estradiol-17 beta-sulfate, estrone glucuronide, and estradiol 17-beta-glucuronide.
 6. A system as claimed in claim 1, wherein said cleavage of said biological conjugate releases a ligand selected from the group consisting of 17-beta-estradiol and estrone.
 7. A system as claimed in claim 1, wherein at least one of said promoters in said DNA constructs of steps a), b) and c) is an inducible promoter selected from the group consisting of CUP1, HSP70, HSP26, HSP104, SSA4, galactose-inducible promoters, GAL1, and GAL10.
 8. A system as claimed in claim 1, wherein at least one of said promoters in said DNA constructs of steps a), b) and c), is a constitutive promoter selected from the group consisting of ADH1, GPD, and CUP1.
 9. A system as claimed in claim 1, wherein said first, second and third DNA constructs are expression vectors, wherein each of said expression vectors comprises sequences which enable replication in both prokaryotes and eukaryotes.
 10. A system as claimed in claim 1, wherein said host cell is selected from the group consisting of a yeast cell, an insect cell, a mammalian cell, and a bacterial cell.
 11. A system as claimed in claim 10, wherein said yeast is Saccharomyces cerevisiae.
 12. A system as claimed in claim 1, wherein said reporter gene is selected from the group consisting of β-galactosidase, alkaline phosphatase, green fluorescent protein, red fluorescent protein, chloramphenicol acetyltransferase, and surface molecules recognized by immunospecific antibodies.
 13. A system as claimed in claim 1, wherein said biological sample is selected from the group consisting of allantoic fluid, blood, urinates, saliva, culture media of test animal tissue and extract from test animal tissue.
 14. A system as claimed in claim 1, wherein the construct of step b) comprises a plurality of response elements selected from the group consisting of estrogen response elements, androgen response elements and nuclear receptor response elements.
 15. A method for detecting the presence of sex determinative ligands which transactivate nuclear receptors in a ligand-dependent manner in a biological sample, comprising: a) providing a host cell containing a first DNA construct having a nucleic acid molecule encoding a receptor having binding affinity for a sex determinative ligand operably linked to a first promoter; a second DNA construct comprising a second promoter containing a plurality of sex determinative ligand response elements, said second promoter being operably linked to a reporter gene and a third DNA construct comprising a nucleic acid sequence encoding an enzyme for cleaving a naturally occurring biological conjugate, said biological conjugate comprising said sex determinative ligand, said nucleic acid sequence encoding said enzyme being operably linked to a third promoter sequence; b) contacting said host cell with a biological sample suspected of containing said sex determinative ligand; and c) assessing levels of expression of said reporter gene in said host cell, said expression being dependent upon cleavage of said sex determinative ligand from a biological conjugate if present, in said biological sample.
 16. A method as claimed in claim 15, wherein said first DNA construct encodes a receptor selected from estrogen receptor alpha, estrogen receptor beta, androgen receptor, progesterone receptor, glucocorticoid receptor, adrenocorticoid receptor, thyroid hormone receptor alpha and beta, retinoic acid receptor alpha, beta and gamma, retinoic acid X receptor alpha, beta and gamma, peroxysome proliferator activating receptor alpha, delta and gamma, vitamin D receptor, dioxin receptor, and liver X receptor isolated from different organisms.
 17. A method as claimed in claim 15, wherein said third DNA construct encodes an enzyme selected from the group consisting of beta-glucuronidase, alpha-glucuronidase, and sulfatases.
 18. A method as claimed in claim 15, wherein said biological conjugate is selected from the group of conjugates consisting of estrone-sulfate, estradiol-17 beta-sulfate, estrone glucuronide, and estradiol 17-beta-glucuronide.
 19. A method as claimed in claim 15, wherein said cleavage of said biological conjugate releases a ligand selected from the group consisting of 17-beta-estradiol and estrone.
 20. A method as claimed in claim 15, wherein at least one of said promoters in said DNA constructs of steps a), b) and c) is an inducible promoter selected from the group consisting of CUP1, HSP70, HSP26, HSP104, SSA4, galactose-inducible promoters, GAL1 and GAL10.
 21. A method as claimed in claim 15, wherein at least one of said promoters in said DNA constructs of steps a), b) and c), is a constitutive promoter selected from the group consisting of ADH1, GPD, and CUP1.
 22. A method as claimed in claim 15, wherein said first, second and third DNA constructs are expression vectors, wherein each of said expression vectors comprises sequences which enable replication in both prokaryotes and eukaryotes.
 23. A method as claimed in claim 15, wherein said host cell is selected from the group consisting of a yeast cell, an insect cell, a mammalian cell, and a bacterial cell.
 24. A method as claimed in claim 23, wherein said yeast is Saccharomyces cerevisiae.
 25. A method as claimed in claim 15, wherein said reporter gene is selected from the group consisting of β-galactosidase, alkaline phosphatase, green fluorescent protein, red fluorescent protein, chloramphenicol acetyltransferase, and surface molecules recognized by immunospecific antibodies.
 26. A method as claimed in claim 15, wherein said biological sample is selected from the group consisting of allantoic fluid, blood, urinates, saliva, culture media of test animal tissue, and extract from test animal tissue.
 27. A method as claimed in claim 15, wherein said second promoter comprises a plurality of response elements selected from the group consisting of estrogen response elements, androgen response elements, and nuclear receptor response elements.
 28. A method as claimed in claim 15, wherein the activity of said reporter is determined using a method selected from the group consisting of determination of enzymatic activity using enzymatic substrates, detection of protein encoded by said reporter gene using an antibody immunologically specific for said protein.
 29. The method as claimed in claim 28, wherein said reporter gene encodes a fluorescent reporter protein.
 30. A kit comprising the test system of claim
 1. 31. An estrogen dependent transactivation system for gender-sorting in avian species, comprising; a) a first DNA construct comprising a nucleic acid molecule encoding an estrogen receptor operably linked to a promoter; b) a second DNA construct comprising a promoter containing a plurality of estrogen response elements, said promoter being operably linked to a reporter gene; c) a third DNA construct comprising a nucleic acid sequence encoding a glucuronidase enzyme for cleaving a naturally occurring estrogen-glucuronide conjugate, said estrogen-glucuronide conjugate comprising estrogen, said nucleic sequence encoding glucuronidase being operably linked to a promoter sequence; d) a yeast cell comprising said first, second and third DNA constructs, expression of said reporter gene in said yeast cell being dependent upon release of estradiol from said glucuronide conjugate present in an allantoic sample of an animal, reporter gene expression levels being correlated with the presence of a ligand which indicates a sex of said animal; e) media for yeast cell growth and enhancement of glucuronidase expression, secretion and activity; and f) a substrate and protocol to assess said reporter gene expression.
 32. A method for detecting the presence of estrogen [which transactivates nuclear receptors] in a ligand-dependent manner in a biological sample, comprising: a) providing a yeast cell comprising a first DNA construct having a nucleic acid molecule encoding an estrogen receptor operably linked to a first promoter; a second DNA construct comprising a second promoter containing a plurality of estrogen response elements, said promoter being operably linked to a reporter gene, and a third DNA construct comprising a nucleic acid sequence encoding a glucuronidase enzyme for cleaving naturally occurring estrogen-glucuronide conjugates, said nucleic acid sequence encoding a glucuronidase enzyme being operably linked to a promoter sequence; b) contacting said yeast cell with a biological sample of an animal suspected of containing estrogen; and c) assessing levels of expression of said reporter gene in said yeast cell, expression of said reporter gene being dependent upon release of estradiol from said glucuronide conjugate present in said biological sample, reporter gene expression levels being correlated with the presence of a ligand which indicates a sex of said animal.
 33. The method of claim 32, wherein said biological sample is selected from the group consisting of allantoic fluid, blood, urinates, saliva, culture media of test animal tissue, and extract from test animal tissue. 